The pocket press is a valid explanation, but it has yet to happen to me. I'm a big guy w/ a lot of stuff in my pockets as well. so you would think it would be a regular thing, but it's just not the case.
My key has unlatched inside my pocket before but I've yet to experince trunk openings or alarms.
Ordered 1/9/12 - Born 2/3/12 - Delivered 2/21/12 - '12 1SS/RS Summit White - TRADED.
2014 SS Performance Sedan - Red Hot 2 - Black Leather. S/R. Full size spare.