This is a bit of a weird one, and reproducing it will probably be pretty hard, but here is what happened:
- Raid happens, gets repelled by pets
- Raid tries to kidnap, takes my last pawn who couldn't move anymore anyway
- Runs away, gets struck by alpaca.
This is what happened: http://i.imgur.com/CFNbEqs.png
Both the raider and the alpaca just standing there. Alpaca has no task queued, the raider has "digging at marble wall". After some time, both the raider and alpaca went to sleep. I'd expect the raider to either meele the alpaca or run the other way.
Yeah, this is sort of a known issue. There's an asymmetry with the melee blockage system.