OBG, You didn't have to bring that up. Have done the same thing, sweaty hand slipping off of the little metal grounding clip. But getting zapped by a lawn mower plug many years ago made me very careful when i moved up to working on car ignition systems.

Have a friend of mine that was popped by one of the modern automotive hei systems told me that he wasn't sure which was worse, that or getting hit with a taser. (Getting hit with a taser was part of his LEO training) He said that both put him on the ground.