Sent to me via e-mail:

I didn't know this was ever questioned. It has always been that it only detonated if your maneuver template went over it or if you ended your movement on one, not if you started overlapping it. *shrug*

Keep in mind, if you start your turn and if even just a tiny bit of proxy mine peeks out between the template guides on the front of your ship, it blows up on you.

This question was in response to a tourney situation that occured where a falcon started on a proximity mine token. The T.O. ruled it blew up as soon as the falcon started to move, even thought the template or final base position never touched the mine template. The confusion occurs with overlapping only being defined as when moving and having your template or base overlap something, not if you have something slide under your base before your move has begun.

It runs in the "simultaneous" and "being hit" vein of counter intuition that crops up with language based rule development.

Sounds to me like a TO that doesn't pay attention to the rules. The rules are very clearly defined, there should be no misinterpretation of how it works. If I were the player at that tourney I'd be pissed. It works the same way as asteroids, if you overlap an asteroid, you don't roll for damage a second time when you move off of it (unless the same issue arises where there is still more asteroid peeking through your front guides). I don't understand why a TO would think the proxy mine acted any differently.

Hopefully this info from FFG will prevent this sort of thing in the future. Thanks for posting it!