Insane GTA San Andreas speedrun glitch

[Mave]

I had to pause this constantly in order to comprehend the insanity that is this glitch.
How on earth does someone even figure this out?
Sidenote: I hate these kind of glitches and prefer normal speedruns without game breaking strats, however I’m impressed with this one.

 

[Stybar]

What the fuck.
How do you even figure this shit out? It's insane.