Funny I remember a post like this a few months back in which the OP was told it wasn’t the SO’s fault she had a mare. Except her mare didn’t have a few scratches, she got pretty banged up.
IIRC that thread was about a mare that backed up to the fence and kicked at the neighboring stallion through the fence and cut herself up pretty badly. The stallion stayed on his own side and the mare injured herself. Big difference IMO between that and a stallion coming through or over a fence and breeding mares on a different property.