Well I have to be careful about discussing this lest I be taken to court...
But yeah he cheated.
Essentially the way MAME (or another emulator) will load levels and such is different than how the original arcade boards will load screens. So there are certain little visual things that happen on MAME that will not happen on legit hardware. In the videos for at least two of his million+ scores there are certain visual effects that happen on MAME but not arcade hardware. It seems pretty open shut.
Of course there's the possibility that he played on an emulator but still didn't cheat, but the use of emulators itself is a no-no, and leads to suspicion.
The videos show what they show so whoever he's essentially placing eye witness testimony against video evidence, and the video evidence is going to win out.
Ahhhh. Thanks for the breakdown. It would be unfortunate if, as you said, he played on an emulator and didn't cheat, but wadrugondo? He knew the rules and broke them.
The thing is, as I understand the situation, is that he specifically submitted the score in the original hardware category. There's nothing inherently wrong with playing it on MAME or some other form, because not everyone is going to have access to an original DK machine. But you can't submit an emulator score in an arcade category.