Well, i think it comes down to sensible logic when using mechs. Know what the limits are with whatever tank/build you stick on it, don't leave the battery inside when not in use..don't put it in your pocket, just in case it fires, as there's no cut off safety built in...and of course, make sure the batteries are in top notch condition. Just simple logic when dealing with them.
My mech will be taking 18350s...the latest kind, so 10 amps max..but i'm not intending to stick a build on it that'll get anywhere close to to that, as that'll be 0.4 ohm build. As a MTler..i'm probably going to hang around the 1.0-1.2 ohm mark, so it'll around 4 amps mark or thereabouts.
Those numpties who suffer exploding batteries, probably either put too low a build on it, or haven't taken care of the batteries...had them stuffed down their trouser pockets..and so on.
Mind you..i'm just repeating what i've read up about mechs...i haven't tried one yet!