Well this is too much of a coincidence.. each time we tame mouflons there is a server crash.
Maybe this will help to pinpoint the problem:
We had a herd fenced in one location and a single mouflon at a separate location.
Both me and xcom were taming different sheeps in the fenced-in herd.
I had an alt jumping me in spar mode. I think xcom had one too.
Also my char that was taming was in party with xcom's tamer.