I'm convinced that the problem is simpler than that.
A small cylinder trying to slide through a larger cylinder will bind if there is enough play between the two and if the smaller cylinder is not pushed through directly.
I just think that the button has way to much room to twist when it is being pushed.
Seen here in the full upright position.
If you catch the button off center it will do this. There is no reason there should be so much play in this button. It jams there. And not only when you turn it on. It can also jam this way when you try to turn it off.
I think that the tolerances were just not tight enough.
Still waiting on Four Sevens to respond to my e-mail.
Eeewwwwww, that looks really bad. Hopefully they fix up those tolerances pretty fast.