I had a raid, and fought them off, then chased the fleeing people down. One of the attackers was wounded but not killed. I decided I didn't want to capture them.
Then I caught one of my colonists scurrying out the door clutching my precious meals to feed to the downed attacker, even though the attacker wasn't captured or part of the colony. I've noticed this happening before with other random events such as escape pods.
http://i.imgur.com/Gkz6rUf.jpg
Yep, already known bug.