Just my opinions and no offense intended. Why did you hang the carcass in a meat locker? It is a sure way to make game taste even gamier. Yes, it will be somewhat more tender, but it tastes bad.
Clean the carcass instantly, cool the carcass instantly, and butcher and quick freeze the meat absolutely as soon as possible. The quick freeze tenderizes the meat. You will be amazed at how much better the meat tastes.
Also, in my 40 years of deer hunting, I have never heard of marinating meat for 5 days. As another responder indicated, one day is more than enough.
Very likely that the bad flavor was due to a combination of many factors.
Hope this helps.
Mannyrock