My companion has killed me plenty of times. but the amount of times they have saved my life is far greater.

Quite a few times.

Several because they often leap in front of me so I have to stop doing what I`m doing, giving theenemy time to cast mighty spells in my face.

I had one Follower once who instead of staying in stealth with me, decided it was time to attack a hord of enemies bringing them all down on us, which killed us.

I often have to play a careful game with my Followers (like leaving them way back) if I want to spy out an area.

p.s Oh yes, traps too. I evade a trap trigger, walk on and the trap explodes in flames killing me and putting my Follower in stupid `kneel` mode, because my Follower walked on it.