Wow, what memories! I was there, Bono had been having problems with the mic for a while, I can't remember, but at least in one more song and nobody realised he wanted to change it, when it stopped working he got, well, you can see, really angry, but I think he overacted it as he saw the public were cheering, later on he apologised with the crew, he said they were the best people one could work with and dedicated them a song.