I had 2 BS deaths the other day on MW2.
The first happened on a game of demolition, I was heading towards the bomb when I saw a claymore 5 feet in front of me pointed the other direction. I backed up a few steps and got ready to shoot it when it exploded for no reason at all and killed me. nobody had set it off or shot it and I was out of it's blast radius. I was rather pissed.
the second was a deathmatch on rooftop. I had been killed and finished the killcam and as soon as I respawned, I saw my body falling over and another killcam started. Apparently, a guy was sniping and shot a guy through the head at the instant I had respawned and the bullet went through his head and into mine. although it was funny.