Oh man... I knew this was coming Xp
As some of you may know (from visiting SCD), I'm a friend of Nelspike's. I was actually online in an MSN convo with him at the time that he got these scores last night. However, when he was actually telling me about them, I wasn't really focusing that much, as I was busy doing work on Sonic Heroes myself (and getting a bit riled with the game... *ahem...*), so I was just saying 'good work' and such to them. It was only once he told me he submitted these stats before disappearing offline that I noticed how hefty the scores he got were in comparison to the existing records. Upon seeing them, I expected there was likely to be some BS calls on them. If I had paid more attention when he stated them as he got them, I probably would've quizzed him on them.
Anywhos... I would suspect that he used the 9:59 bonus to get the scores. The breaks between him telling me he was going to try an act and stating his score was a long period of time, maybe 10 minutes or more. I expect he probably overlooked the rule stating that acts in Sonic 3/& Knuckles cannot be completed in 9:59 when he read the rules page (he's only recently begun using the system, so it's possible to overlook some things without intention).
Of course, I can't really act as a proper defence for him, since I'm not sure what exactly he did, for the reason I stated at the beginning, so I'm only assuming ^^;; But I thought it would be best to give some incite on what has likely happened. I'll probably catch up with him later, so I'll tell him to stop by here and explain what he did to get those scores when I do.