You are exactly right he did pee on himself. What you smell are the tarsal glands of a buck in the rut. The first thing I do when hanging a deer is to remove the tarsal glands. (Learned this from a guide in Wyoming back in '71.)
    You need to rinse the carcass after skinning, if you haven't cut it yet. If you've already cut it, rinse the pieces. If that doesn't work dissolve a 1/4 - 1/2 a box of baking soda in cold water and then through the meat in and swish it around. That should do it.

Dave

Tarsal gland removed: