The ironman wasn't clean at all.
The whole story of the match was Brock cheating like mad to win the title
Barron, you're missing the point. Yes, he cheated, but he took falls for that. He sill had to overcome those falls. Also, the FINISH saw him trapped in the same Anklelock he had been in a couple of times in the match already. the same anklelock that made him tap clean TWICE at SS. The same anklelock that garnered the "you tapped out" chants from the fans for weeks leading up to this confrontation. Not to mention the famed "heel lock" that forced Chris Benoit to tap and give up his title quest in favor of Brock going on the hunt thast year. Brock stayed in it and went the distance. He didn't tap, and Kurt wasn't able to regain enough momentum to beat Lesnar who at one time was up what, 4 falls? CLEAN.