I've had the same accident happen with my Quark AA which activated when it was in my gym bag, it was wrapped around my towel when it activated. It must have been on for a long time coz I was able to start feeling the heat from outside my bag. Though it didnt fry the light, It did however, ruin the O-rings.
You might want to replace the O-rings of your light if you are concerned about it's water-proofness.
Luckily I had just odered the o-ring package of Foursevens and replaced the o-rings right away.
Light still works as good as the day i bought it, well, with the dings and all.