Who was McScotch?

I recently purchased a reprint of the book "Fighter Pilot", originally published in 1936 and written by a 40 Sq. RFC pilot who identifies himself only as McScotch, a nickname he claims to have been given in 1917 by his friend and comrade at 40 Sq., Mick Mannock. The jacket claims McScotch was a Captain and 12 victory ace himself, but it still doesn't identify him by his real name. Is anyone else familiar with this book? Who was "McScotch"? It has some interesting material which I would bring here, but I'd like to have a better idea of its accuracy before I begin citing it as a valid reference. He also notes that he and Mannock returned to Blighty after their first tour and expected to go back to the front together in 1918, but "circumstances prevented" McScotch's return to the front. Anyone know what that cryptic bit was about? I've never been a big Mannock fan, but if McScotch is for real, I think I may have badly misjudged Mannock.