Today I was playing Nader on trainyard when following happened:
- ) Switched to the ability and shot some nades
2 ) Jumped into the train to kill enemies.
3 ) As soon as I entered the train, my character automatically planted the C4. I only could stop it when switching to other weapons, but my character switched back to C4 and started planting again. During this I got killed 
Happened in the last seconds of the game, so I could not retry this.