This is real and pannenkoek, aka mario parallel universes guy, had a 1000 dollar bounty for anyone who could reproduce and record this up-warp glitch.

No one could do it, even when copying the movement in the footage of the glitch exactly. Its pretty much accepted now that it was because of some kind of radiation or interference flipping that one bit responsible for his position because no one has been able to do it after all these years, and tests show that manually flipping that bit at the location he was at gives extremely similar results.