According to Shores, et al, in
Above The Trenches, 85 Sqn flew to France on May 22nd, 1918. Bishop's last successful flight with the unit is on June 19th.
Between May 27th and that latter date he destroys 24 enemy machines, and drives one down out of control. Eleven of the 25 official victories are accounted for in merely three days, May 30th, June 17th, June 19th. I don't believe that any of the 25 are shared with wingmen, and very few are witnessed.
I stand to be corrected on this, but I think that every mission is completed without a forced landing, without any engine failure, without structural damage, and without wounds.
It is the combination of the above facts that causes me to wonder about the record, not merely that a talented ace can rack up a large score in a short period.
I would be curious to know when Bishop officially joined the CAF in England? Was it in June, or not until August?