In retrospect, I think the initial abstract of the paper ("Berg and Ulfberg and Amano and Maruoka have used CNF-DNF-approximators to prove exponential lower bounds for the monotone network complexity of the clique function and of Andreev's function. We show that these approximators can be used to prove the same lower bound for their non-monotone network complexity. This implies P not equal NP.") was also a way to have as many people as possible double check the proof, due to the very strong result of the paper.

In other words, he might not have been building up the hype but instead was making sure he wouldn't have to retract a paper with a (more or less) obvious mistake in it. That's how science should be done rather than behind closed doors !