Darth Vaders Force Choke cancels itself after a second

Every now and then this bug is reported again here in answers hq. Curiously, I play with vader frequently, and this bug has never happened to me even once.

What I do know is that his choke ability can be cancelled by pressing the ability's button again while performing it.

So I always wonder if people aren't doing that by mistake, or if their controller/M&K is malfunctioning