1) What the circumstances were : i used a psychic shock lance to "shock" a pawn
2) What happened : no "shock" , just insta kill whith no injury http://imgur.com/cHm8CVW
3) What you expected to happen : to incapacited him with a possibility to cause brain damage (shock lance description)
4) Steps we can follow to make the bug appear on our machine : just use the psychic shock lance on people and Watch them be insta killed most of the time.
It's to prevent players from having too many colonists, so it's working as intended. For each newly downed pawn there's a chance he will instantly die. Thanks for reporting anyway.