OK my zmax just did it again and I did nothing so I could watch it.
The light was not on. But my juice was still popping like crazy. There's no way the current wasn't flowing through the wire still. And it wasn't that it was over hot or anything because as soon as it stopped I took a hit again right away and it was normal, cut off as soon as the button was released.
It's the crappy button on the ZMax. I like the button on the V2/R4 VMax alot better. When I'm toking on the ZMax it will go into the menu settings even though I didn't click the button 3 times...really annoying.