In Ch.3, s.1 ["Tribunals: Overview"] I make the practical distinction between the presiding tribunal and the managing tribunal, a distinction little acknowledged in law. In addition to the authority of a presiding tribunal to make orders in any particular proceeding to control it's procedures and practices [SPPA s.25.0.1(a)] and to maintain order [s.9(2)], the managing tribunal may also make s.25.1 rules with respect the procedures and practices of the tribunal generally (applicable to all presiding tribunals) [SPPA s.25.0.1(b), 25.1].
Note that all of the above-mentioned authorities are distinct from the SPPA's similar-sounding "abuse of process" jurisdiction [s.23(1)] that is discussed in Ch.10, s.5 ["Abuse of Process"]. While the legal doctrine of 'abuse of process' is a developing and flexible one, in this context it likely relates more to situations where the bringing of the proceeding itself (rather than any specific behaviour or conduct within it) is legally problematic (eg. a prior proceeding has already resolved the issues in dispute, creating a 'cause of action' estoppel).
As per the discussion of the MTHA v Godwin Court of Appeal case in Ch.1, s.2 ["Tribunals and Their Rules"], all these authorities will likely be interpreted broadly.
In Nyonzima v Human Rights Tribunal of Ontario 2012 ONSC 5120 (CanLII) the Divisional Court considered a judicial review application from an HRTO applicant whose case was not only dismissed, but held to be an abuse of process. The HRTO finding of abuse of process (rather than a simple dismissal) appears to have been motivated by a finding that the applicant had attempted to introduce forged letters into evidence. The court, citing the high level of review deference to be accorded to the HRTO both by reason of it's institutional expertise and that it was engaging largely in fact-findings in reaching it's conclusions, dismissed the judicial review.
In Dai v. Presbyterian Church in Canada (Ont Div Ct, 2013) the court held that a tribunal's authority to control it's own processes extended to the ability to declare an applicant a vexatious litigant and bar him from commencing future proceedings before it without the consent of the tribunal. The court did not address which specific SPPA provision grounded this authority, nor whether it was a general SPPA authority or one that required s.25.1 rule-making by the tribunal - which is unfortunate given the several potential statutory sources for such authority.