I feel like sniping a gym from an opposing team is fair game in *battle*, it's pretty shitty to do that to your own team with training levels! (My other sop to my conscience when I snipe gyms is to land something with low CP in the slot, so that it's easy for my team to level up a spot, and relatively easy for an opposing team to take it back. (My context is that all the gyms near me change hands multiple times an hour, and I've lost the gym in the time between battling-to-zero and getting the menu to post a #mon multiple times, so - in my context this seems ok *for battle*)