Hey Flamewave. Though I'm sure I don't holistically understand all of the mechanics involved with zapping things, I can tell you what I have experienced. I'm currently playing co-op with a buddy of mine, and he is using a wizard that uses a lot of electricity spells. My character is a Knight/Witch combo, so I play in the middle of the pack. Any time he uses a spell or attacks using his electric wand, I have to make sure I'm not in the way of a stream of lightning. I know that if I'm standing in water that I'm going to get stunned. I think those are the only two ways to get popped, but I could be wrong. I hope that helped.
In the first fight aganist the zombies (outside the tutorial dungeon), the PC's are sandiwched between the enemis. If I use a lightning attack, I end up stunning all.
Is it becuase the bow zombies also make the PC's wet?