Probably something to do with most meter monkeys being too thick to know how to handle the stuff! I was talking to a woman the other day, her friend has just had a rather nasty fire in her meter cupboard, the service head caught fire, apparently whoever came out from the DNO, said it was just bad luck and didn't happen that often.
I said that if she'd recently had a meter change, then it was more likely that it hadn't been tightened correctly, she's going to ask her if the meter has been changed. It's becoming all too common, most network guys I speak to have seen loads of these issues recently. the trouble is sometimes the problem is covered up, or at least they try to.
A couple of years ago I was called to a mini mart, the owner is a friend of mine, he'd opened up that morning to find the place smelled of burning and he'd discovered a smouldering fire at the intake position, the head had caught fire. He rang the DNO and they arrived around the same time I did, the head was toast, the back board severely damaged, and the incomer needed replacing.
The cable from the live terminal was very loose, obviously it had not been tightened properly! I pointed this out, and the guy said they often came loose during a fire, I thought this was complete BS and said so, service heads don't just spontaneously ignite. The fact that he'd recently had a meter replaced also heightened my suspicions. My theory was borne out to a great extent, when, all of a sudden they went from, "you'll have to close the business while we sort it" to "don't worry, we'll set up a temporary generator so you can still trade while we do the repairs".