A lot? What, two, maybe three?? So far as I know, Caldwell, Fry, and perhaps one other from his squadron of the time have expressed their doubts.
As to those who were not preset, Mannock supporter, and someone whom we can say almost definitely "streched the truth"
Taffy Jones. And then there's Fred Libby. Who so exaggerated Bishop's claims as to make some of us wonder who he was REALLY talking about.
The people I would have expected to say something derogatory about Bishop, those under his command in 85 squadron, did not. At least, so far as I am aware, they have not said anything publicly.
So far, to date, public comments that are negative about Bishop pale in comparison to accolades. Perhaps this is not an accurate barometer, but with the apparent lack of any other proof, we haven't much to go on.
Certainly, Greenhous was pulling tricks out of his sleeves to write his book.
VBR,
Al Lowe