I say what I see, on my server (0.3.6pl1), if at the end of the funciont it returns a false players dont die, even if they are not in event, I changed it to true and problem solved, if they are on event that problem dont exist 'cause when value > currHealth, as you said, they get tp to temple, but if they are not in the event they dont die and dont get tp to temple 'cause they are not in event zone
and of course you have tested the script, but its more probably that other ppl find a bug or an error than you (even if you have scripted it you cannot be sure at 100% that this have no errors)