It was emulated. Is there a difference among those? Because I also have this game on my PS2 in Sonic Mega Collection Plus, and there doesn't seem to be a difference in physics.
The original title of this was going to be "Sonic Generations: Green Hill: Act 2: Fastest Time without Drift." I guess the mods changed it. And yes, this was done on pc. It is much easier on the console version though, since on the console version you CAN drift. Not on pc.