I keep reading this argument that because article 64 proceedings are ‘SUI GENERIS,’ (to wit of its own kind; unique) somehow, known rule of evidence do not or should not apply, and that the common law-based adversarial system of justice should be swapped for or mixed with the civil law-based inquisitorial system.

I disagree. The law is still "he who alleges must prove," irrespective of the kind of case it is. I say so for the following reasons:

1. The court has pronounced on this ‘sui generis’ matter several times. In SABBAH v THE REPUBLIC, Wood CJ said “a constitution being sui generis must be construed in the light of its own wording and not on the basis of words found in any other constitution, let alone the statutory provisions of another jurisdiction, would not permit this.”
   
   In NPP v GBC, the court said “a Constitutional document must be interpreted sui generis to allow the written word and the spirit that animates it to exist in harmony. Reference must be made to stated objectives in the Constitution so that the emphatic pointers to its spirit are not missed. The Constitution itself points the way to its liberal interpretation.”
   
2. In KUENYEHIA v ARCHER, Francois JSC said "any attempt to construe the various provisions of the Constitution, 1992 relevant to the present inquiry must perforce start with an awareness that a constitutional instrument is a document sui generis to be interpreted according to principles suitable to its peculiar character and not necessarily according to the ordinary rules and presumptions of statutory interpretation.
   
   Though basic rules of statutory construction may provide the first steps, they should strictly be kept at the first rung as servants and never elevated in flight as maters.” And in EX PARTE CHRAJ (RICHARD ANANE CASE), the court said “a well-established principle of constitutional construction is that a national constitution is sui generis and must be interpreted according to its own character or wording.”
   
   None of these cases support(s) this rather strange contention on the non-applicability of our known rules of evidence.
   
3. When article 64 provided for the filing of election petitions, it did not also provide for the rules of evidence, or practice and procedure that would apply. On the latter, because no existing rules of practice and procedure existed, the article was careful to specifically vest the power to make them in the Rules of Court Committee.
   
   I posit that article 64 did not need or have to make a similar provision for the applicable rules of evidence because we already have them in statute. That is why I find it difficult to accept that the courts could or should literally make up or conjure rules of evidence that would apply, notwithstanding the rules in the existing Evidence Act.
   
4. The Evidence Act constitutes part of our laws both as statute on account of article 11(1) and as “existing law” under article 11(4). Clearly, absent any specific provision in article 64 that would point to or suggest that another set of evidentiary rules should apply, the existing rules under the Evidence Act will apply to every matter before our courts.
   
   To the extent that the statute is not being used to specifically defeat the letter and spirit of the Constitution (and I do not see that that is happening, yet), I find no basis in an argument or suggestion that seeks to turn the existing evidentiary rules on their heads and urge adopting any hitherto unknown and inapplicable rules of evidence.
   
5. Section 1(3) and (4) of the Evidence Act says in part that the court determines whether a party has met the evidentiary burden, and that the failure (add: refusal or neglect) to meet it, means the case will be determined against that party.
   
6. Under section 10, the burden of persuasion still is “the obligation of a party [not another party] to establish a requisite degree of belief concerning a fact in the mind of the tribunal of fact or the court,” involving the requirement to “establish the existence or non-existence of a fact by a preponderance of the probabilities.”
   
7. Under section 11, burden of producing evidence still is “the obligation of a party to introduce sufficient evidence to avoid a ruling against him on the issue,” involving the requirement of “a party [and no other party] to produce sufficient evidence so that on all the evidence a reasonable mind could conclude that the existence of the fact was more probable than its non-existence.”
   
8. Thus the basic rule of evidence is and remains that except in the known exceptions (to wit statute, implied or criminal defence and on specific trial issues), the burden of persuasion does not shift. It remains on the plaintiff/petitioner/applicant. It is the evidentiary burden that shifts, and even then, only when that burden has been discharged.
   
9. Therefore, where a plaintiff announces that "the plaintiff has closed its case," that plaintiff is in effect telling the court that the plaintiff has completely discharge its burden and (more importantly) that if only the evidence that it has led is considered in the matter, the plaintiff should win the case.
   
   In other words, if the defendant does not lead any evidence to contradict what you, the plaintiff has led, the plaintiff should win. And so, you then hope that your opponent (the defendant) will be unable to meet its evidentiary burden.
   
   If your opponent then claims that it will not lead evidence, then the matter should go to judgment where the court has only your evidence to evaluate. Hopefully, the matter will end in your favour – but only if you have discharged your probative and evidentiary burdens.
   
   It is never the law, that when a plaintiff closes its case, it can then claim that its case also depends wholly or partially on a defendant (or any other person) testifying. That claim in and of itself admits that the plaintiff has not fully discharged the probative and evidentiary burden, and that it should lose the case.
   
10. And, contrary to the arguments of the APOSTLES OF SUI GENERIS, this rule applies whether the case is a civil case invoking private or public law, or is a constitutional matter.
    
    That is why in MENSIMA v ATTORNEY-GENERAL, Acquah JSC (as he then was) said: “The requirement for proof of an allegation in a trial applies to all branches of legal suits, including that of constitutional law litigation… The standard of proof is the civil standard of a preponderance of probabilities, which must be vigorously applied.”
    
11. And, notably in NDC v EC (COUNCIL OF STATE ELECTIONS CASE), the plaintiff claimed that because some ministers had written letters removing DCEs and government-appointed assembly members, the assemblies were not properly constituted for the purposes of elections to the Council of State.
    
    Even though the defendant denied those allegations, the plaintiff did not exhibit any of the alleged letters. The court, speaking per Acquah JSC said: “The National Democratic Congress did not in its statement of case supply any particulars, nor copies of the alleged letters, neither did it attempt to produce any other evidence in proof of the existence of these letters, in the face of the defendant’s denial.
    
    The substratum of the National Democratic Congress’s complaint therefore remains a mere allegation unsupported by any evidence necessary to prove its validity… Failure by the National Democratic Congress to furnish the relevant particulars, documentary or otherwise in proof of its allegation of the withdrawal of the district chief executives and the government nominees, is sufficient to entitle this court to dismiss the action.”
    
12. Although his Lordship still dealt with the issues raised, for whatever they were worth, he concluded that “In the instant case, since the plaintiff produced no evidence in support of his allegation that at the time of filing this suit, the district chief executives and the government appointees of all the district assemblies, had been withdrawn, he cannot succeed in his quest for a declaration and an injunction to prevent the holding of elections for regional representatives to the Council of State".
    
13. Even though Ampiah JSC dissented (on another ground), he agreed with the rest of the court, saying “To allege that a person has breached a constitutional provision requires the production of sufficient, cogent and clear evidence to support the allegation.
    
    "Unfortunately what we have before us from both sides cannot be said to be sufficient, clear and cogent. In the statement of case for the plaintiff, it alleges that certain letters were written. These letters were the source of its allegation. Yet, these letters were not produced before us.
    
    "No dates were given of these letters and they were not even mentioned as some of the documents relied on. The defendant on its part referred to notices for the conduct of the elections, dates for such elections and the list of persons nominated for the electoral college elections.
    
    "Yet, these notices were neither produced before us, nor were they referred to in the list of documents relied on. Of course, generally, the plaintiff who seeks the declaration or claim and who must succeed on the strength of his own case and not on the weakness of the defendant, must fail in such a situation. In such paucity of evidence as has been presented to us, the court is being called upon to determine the issues in the case.”
    
14. MY CONCLUSION: Unless the Supreme Court decides to depart from these long-standing principles (and providing reasons for the departure, of course), our law, as at today is that HE WHO ALLEGES MUST PROVE.
    
    That also means that you cannot hang the destiny of your case on what your opponent might or might not do in court. If you go to court alleging that something has or has not happened, the burden is on you to provide the evidence.
    
    And that becomes a tad difficult when you have admitted that you indeed have that evidence in your possession, custody and power, but boldly (and probably calamitously) testify that you decided not to bring that evidence to court.