I had the ability to investigate yesterday flying DEL-FRA (not the exact same configuration, but still.)

I suspect the accused may have stood up and peed (with great force and volume) into the corner in front of him. The offending pee spraying via the fuselage onto 8A thus drenching the victim. So he did not need to relieve himself over a sleeping passenger in 8C.

On a different note, the flight was quite good with nice Champagne. But with the size of the glasses and frequency of refills it is not very easy to get plastered.