There shouldnt be anything wrong with the meat especially if the liver looks fine, cause all that deer probably has is gas. I shot a deer with the same thing you explained and i believe it could have been something they eat that could have upset their stomach, which would suggest the bloating and diarrhea but i eat the deer and well im still here alive and kicking so i wouldnt worry about it but if it did come in contact with meat wash it with hot water and a stiff brush and it will kill any bacteria and will get it off the meat.