Hello JoaoMVM!
According to the informations I have there were only two German losses on 10.05.1918: Uffz. Zopf (Jasta 80, killed in a crash) and Lt. Büssing (K4b, killed in action). On this day Jasta 11 suffered no losses.
In contrary Jasta 11 shot down 3 Sop. Camels of 80 Sqn RAF during this day.
So most probably the four claimed Triplanes are "OOC-claims". OOC (out of control) was often accepted as a victory even if the enemy aircraft was not or slightly damaged. Additionally on this day there were no injured pilots reported in Jasta 11.
Source:
The Jasta War Chronology
Hope this helps! *

Volker