I told chadz about this a week ago, as soon as we discovered it after beating the Pecores at Hawaha. Specifically, it would appear the winner of the battle gets all the gear, and nobody loses any gear.
It's not that the attacker's should realistically lose the gear, its that none of it is lost during the battle.
Yeah, not like your vassal didn't launch a major offensive to take out Acre with thousands of very expensive horses that they lost approximately 0 of, you can't really claim the moral high ground here.