Here is a letter which claims to be from someone who was there, although I have no way to verify this. The original may be found at:
www.nationalreview.com/thecorner/04_07_18_corner-archive.asp#036039

Mr. Goldberg --

My wife & I were at the Linda Ronstadt performance in question, at the Aladdin in Las Vegas, and quite frankly, Aladdin President Bill Timmins' account of what happened is complete crap. There was mixed booing and cheering at Ronstadt's pro-Michael Moore comment, and that was about the extent of the "bedlam" that supposedly broke out. I saw no posters being torn down or cocktails being thrown in the air, and if people stomped out of the theatre unhappy, it was because 1) that was the last song Ronstadt performed; it was her encore; and 2) she mainly sang her standards repertoire, with the Nelson Riddle orchestrations, and a large part of the crowd wanted to hear more of her rock-'n'-roll stuff; she got the biggest round of applause for doing a lackadaisical run-through of her version of "Blue Bayou."

Frankly, my suspicion is that Timmins is way overdramatizing what happened, in order to justify giving Ronstadt the boot. It simply wasn't that big a deal.