Also have a final drive leak, but I know what/ how it happened..
I was coming back from a STOC event and heard a loud snap.. Pulled over and saw that my tie down strap had gotten torn off,, I had the excess length of the strap ( typical 1 inch wide nylon strap ) tied up and out of the way, but it had come loose and I thought it had gotten caught under the rear tire, ripped off a hunk and was left in the dust..I saw no other damage and continued my journey home..
Later, I saw my rear tire was flat from a slow leak , and decided to replace the rubber.. good thing.
When I removed the rear wheel, I found about 4-5 feet of the nylon strap had somehow gotten into the rear dive and was tightly coiled up around thee space where the oil seal is . I removed it and did not see any damage other than the wheel was greasy .
Cleaned everything up and went to change the final drive oil and ony about 1 ounce came out.
Filled it back up and a short test ride around the block and it was dripping oil.
I have now pulled the oil seal off, it was a bit looser than I thought it should be as a small pick easily rotated the seal .
Don't see any damage to the oil seal, but it had to be severely compressed by the tie down..
The ball bearing look ok, and turn ok. so I will order the new seal and hope it did no further damage,.