Before tobacco companies were forced to make regular cigarettes "safer" by putting themselves out to avoid burns, I never had any problems with burnt holes on clothes, furniture, etc. After the "FDA is going to save you from yourself" regulations on cigarettes, I would pick up my cigarette from the ashtray and on the way to my mouth or even while I was drawing from it in my mouth, the whole lit wad of tobacco would dislodge from the cigarette and fall on my clothes or furniture. I had to get that out there for some reason...
In the 14 months I've been vaping, I've never had any mishaps with my batteries. I put such incidents together with the chances of a flashlight catching on fire while being lit; and, with cell phones exploding while I'm using them touching my ear and my face/head. Heck, cell phones have been accused of causing brain tumors!
Not saying it wouldn't happen, but what are the chances of all these things malfunctioning to such an extent?