Boolean variable only switches one-way [SOLVED]

I have a boolean variable that I'm trying to switch depending on its status when you press a button. However, using this setup it only switches one-way and will not switch a second time. Am I misunderstanding sub-events on a fundamental level with this?

The project can be found here; the relevant event sheet/layout is "Options".

EDIT: I think this thread might have the answer. Will test...

EDIT 2: Yep, that was it. In case someone else ever runs into this problem:

I didn't have an "else" block between the two sub-events, so the top sub-event changed the variable to false, and then the second sub-event immediately changed it back to true.