That is an interesting idea. But there are motor programs that don't use verbal working memory. Making conscious adjustments (different from how the program was practiced) could interfere, though.

I think physiological panic/fear has to be a large part of most choke experiences, distinct from any thoughts interfering w/ working memory.

I've also heard of people choking especially because they're worried that their social status may be threatened if they're too good or too bad at something. I don't know if that acts through a different mechanism; I'm just saying that such concerns seem especially distorting on performance.