BTW, for something else I was working on, I read a description of a police officer short stroking his pump under extreme stress. If an instrument has the possiblility of needing a physical manipulation that is subject to such stress effects - one might argue that it is difficult to use given standard human factors analyses.
Short-stroking seems to be fairly common, Glenn. Every course I've attended or given it has reared its ugly head. That's one of the reasons I preferred my Beretta 1201 for serious social shotgunning.