Might be related to how the "no attacking" thing on some minigames doesn't always trigger. >_>
Pretty accurate assumption. Turns out the no push zones were only sometimes triggering for players since the no push zone plugin was creating these zones as trigger_multiples, and the entity outputs weren't firing (they also sometimes don't fire when players walk into a teleporter that takes them into a minigame area).
So I've scrapped all the code and replaced it with basic bounds checking so no push zones should be working. I've also changed the minigame areas so that they're just covered with a new type of "no attacking" zone, so that should be fixed now too.