I took the section 3-2623 is there to define what an unsatisfactory demonstration is, and it does not look to be a subsection of either a partial or full evacuation. The previous sections, 3-2622 (Initiation Signal), 3-2621 (Method of Blocking Exits)., looks to be defining sections that apply to both types of evacuations.

IMO, it seems that the section 3-2626.K.13 it gives the rules for partial when it will be deemed an unsatisfactory demonstration, but does not define what unsatisfactory demonstration is. I would assume that is what 3-2623 is for.

IMO