After many people use a flashlight long enough, something is bound to happen. I've had one for a long time, and have never been so careless while changing the batteries so as to bash the switch.
Also, that explosion incident may have been from reverse charging. I would suggest cleaning the contacts regularly, or just running it on 4AA NiMH. It's lighter that way anyway, which brings me to my only real criticism of it which is that I would prefer a smaller one designed only for use with 4AA.