I would have to agree with the other posts. I would tell him to throw the whole batch away and learn from this episode. Explain the proper way to field dress a deer and why you need to do it asap. Make sure to tell him he also needs to wash out the chest cavity with water as soon as possible after field dressing. Of course he will also need to cool the deer (with ice if it is warm out) and get the deer to the processor as soon as he can. He can hang the deer if it is cool enough outside but the need to be in the shade. I'm sure you probably went over this with him, but rehashing it never hurts.