I never heard of them killing anyone. Though I am sure the resulting shock might be enough to trigger issues in those with weak hearts or injury resulting from pulling away rapidly where a fall or slip can cause a severe injury.

Most of my social circle is people that do custom crazy stuff with things with engines. 1000hp off-road trucks, jetskiis that do backflips, cars into the 9 second quarter mile, basically all installation and repair work done by the enthusiast themselves.

I know several people that have lost fingers. Two that have lost teeth. Two that have died along crashes.

Getting shocked by ignition systems is on par with stubbing your toe.