From the sounds of it he didn't go back and won't,
I wish i was using those split copper sabots. I will from now on. I bet they do a much better job. I don't think the sluggers tear anything....just fly right through. Those copper ones fold open on impact....would have opened him open real good...I'm done with sluggers.
Don't blame the slug for you missing the shot. You run a slug length wise through a deers body it's dead. The last time I hit a deer like that he about back flip. Shot was from the ground slug ended up by the back leg. The amount of energy released inside the body cavity is huge. When I recovered it hadn't it didn't need to.
You missed it happens, but the deer died of that I'm sure.