He may very well get over it. You'll know if he does, since it shouldn't fill with gas anymore. I would also start preparing a quarantine (which I do highly recommend cycling) for now, just in case. That way, at least in this situation, you'll have it ready if there is actually an issue. If it is gas bubble disease in the pouch, you'll want to get it treated, as if left long term, it can eventually make its way into the body cavity, causing irreparable damage and eventually death.