[radorn]

I just checked the entire SNES PilotWings SPC set and nothing sounds like the rocket belt track on the disc. Not the style, not any recognizable melody.
But the more I listen to the disc's rocket belt theme the more it reminds me of the gyrocopter theme in the N64 game. The percussion and baseline are very similar, and it also uses brass, which is also used later in the final theme, although the melody in this case is different. It has quite a bit of "floaty-fluffy"-ness to it later, which seems to follow along the lines of the director's demands.

Then, there's the more familiar hang glider theme, which even starts with the a very similar effect as used for the menues when you confirm an option.
This one is puzzling, and the inclusion of the opening "confirm" SFX suggests to me that someone heard wip versions of the music for the game and then tried to recreate them cheaply for the disc... but somehow not even I buy that.

It would seem that, as you suggest, he didn't really took the time to listen to the tracks, or, maybe, he did, and they are real, and he's just shy about it xD. I don't know. In either case, the disc seems legitimate to me and his answer about it being just some fan arrangement doesn't sound right to me at all.