pmh wrote:Hung by their own petard. Always a favourite.
Hoist.
A petard was a small bomb, not unlike the squib of 'damp' fame.
Perhaps we should play grammarian donkey*...
* A catch game were each mistake saw you get a letter, until the word donkey was spelled (not spelt - that is a type of grain). A bit like killer, for those that play pool.