He is not on the RFC / RAF / RNAS rolls as shown here......
http://www.airhistory.org.uk/rfc/fil...combined_A.txt
The USAS purchased 38 SE5As from Britain in Oct. 1918 the first arrived at Croix-de-Metz early November but a big US contract was cancelled. After the war the 5A was replaced by the Eberhardt SE5E ( mostly for training I think) but the Navy had 2, one on the USS MISSISSIPPI.
Nick