people basically are idiots. Anyone who would swallow something like that, or even put it in his mouth, is from the shallow end of the gene pool and needs to be culled.
had a friend almost end up like that when we were working on a car. we had the car on a lift, he had one wrench in his hand, one in his mouth by the box end, he was looking up to see the bolt he was removing when suddenly the rusty strap that was holding the muffler up broke. the muffler hit the wrench and rammed it into his molars. had the angle been just a little different...