There's way to fight any wild animal (in close combat) without being attacked by it.
Steps to reproduce:
1) Find a fellow and form a party with him/her
2) Stand far enough so you don't see each other (question mark instead of portrait)
3) Make an animal to attack you and kill the game (not just close, but kill the process)
4) Animal will bump once and then get stuck
5) Your friend now may come and kill it without being attacked (It may yet flee, sure).
6) Profit.
This bug was originally reported by grehh, but he asked me to post it as it should be done in English.