No manufacturer will ever have a 100% perfect record. I guess you got a duff one?
But the head breaking off??? C'mon...that goes beyond "one just got out"...sounds like poor machining/material...coupled with poor QC.
My older brother is also military and deploys to "hostile" environments quite frequently...he got one of my old L1's a few years back. My younger bro is an adventurer/outdoorsy guy, and he got one of my G2L's a few years back as well. I couldn't/wouldn't give them anything less.
I'm glad your wife wasn't in a "less than hospitable" situation...it could have broken at a worse time. The things I do, my lights CANNOT fail...if, by an act of God, they do, I'll have a back-up (usually a...well, E1B Back-up...).
I've heard of Surefires being broke on purpose, or extreme "accidents", but have never heard of one failing due to A) Unknown reasons (i.e. giddy electronics) B) Being dropped (minus a busted bulb). On the other hand, I've read stories of SF's surviving extreme accidents, that, well, most MIC lights would not have survived. I tell people at work this...Surefire isn't just a "cool tactical name"...(o.k., maybe it is now), but, it's actually a description of the light..."Guaranteed To Work".
(And yes, there are others, HDS, Peak, Elzetta, etc. al., that have similar track records of "just working", I only mention SF cause that's what I own)
Edit...just realized this was a semi-necro thread, but, the stories are still the same...