technically, Richthofen did not shoot down McCudden's plane. in the book, it clearly states that there are no directly corresponding British losses given the time and location described by Richthofen. they go on to explain that "Vickers" type aircraft were easily confused amongst each other (especially if you're chasing them from behind... a pusher "lattice tail" type is probably gonna look pretty similar in a savage dogfight... and I doubt anybody could distinguish between an FE8 and a DH2 in combat!!!
based on my readings, I think the Aerodrome (and "Under the Guns of the Red Baron") have the most reasonable interpretations of the event.
THAT interpretation makes more sense than the others (with huge time lags between claims and actual kills).
the other funny anecdote is that McCudden describes how he was scarcely damaged (if it all in the fight) whereas one of his comrades (who was attacked by Bohme--the more experienced pilot, if memory serves) was "riddled" in a matter of seconds.