On the three nights we watched Marina Abramovic at the Guggenheim we saw a few people over and over again. One of them we knew was an art critic — mostly from the way she was (at times skeptically) watching the entire thing almost as intently as we were — and a few others we guessed from the surehanded way they handled a reporter’s notebook. No easy task. So we were both vindicated in our guess and totally pissed at ourselves for not saying hi when we found Roberta Smith’s take in the Times. Not quite as minute-to-minute, but she got some things we missed. Like the fact that an EMS team was anonymously called in on the Lips of Thomas evening, almost left, but then came in when they heard there was a naked chick cutting herself on stage.