Inside of cover being wet is either because there is no tight seal(no gasket there) between cover and block,,,,or because front of flywheel cover was pinched slightly over rear of pan leaving a gap between cover and the block allowing oil into cover from your leak source. This is why a leak at rear of pan gasket at rear main retainer can fool one into blaming a rear main seal leak as noted in my earlier post.
Well, you were right. That's the area the leak was coming from, but it sure looked like it was coming out from between the bellhousing and the cover.
