I mean, the video in-question is 100% played on an emulator.
So either
1) He played on an emulator and didn't know it.
2)He played on an emulator and knew it, and claimed he didn't.
3)There is some completely unknown, one-off, version of DK is programmed like a modern emulator.
There are all things that should be pretty much... known, when you're making a world record attempt. Whats more, his skill levels are kinda lacking compared to the more modern players who have since eclipsed his DK scores.