Too late now, but I would have left it in the initial bag and just dealt with the air issue. Since it is a bone in sub-primal did you take steps to cover the exposed bone ends? If not then I imagine you have cut holes in the bag. At this point you need to locate the holes by a careful inspection and place a piece of good sealing tape on those holes. Then works the air to the ends, make a small slit in the bag, insert a straw or tubing and suck out the offending air. Then quickly seal the slits with tape.