For those of you who think he should have linked her size to the way it changed her movements, if he had done that, would you have excused it?
The question is whether or not he owes an apology. Jimithing mentioned Kathy Griffin (Griffith?). I can't stand that woman. She, like Sarah Silverman, makes a living crucifying people to make a joke. However, an important distinction here is that Griffin and Silverman could use anything to make a joke, but they choose people.
This man's job is to critique dance. I don't know nearly enough about ballet to articulate the differences that a woman's body size makes, but I do know that I'm in no position to say an expert is wrong for making a comment about her size. Again, even she said that her body is part of her art form.
I'm really surprised how many people are disagreeing. In a forum where we see restaurant goers say that everything from the music, to the table tents and condiments, to the demeanor of the host/server/manager/bartender affects their enjoyment of their meal, I'm really surprised to see that the *only* thing he should be allowed to criticize is whether or not she did the specific motions well.
All of that aside, there is a question of how he phrased it. I see his job as two parts. One is to critique dance. The other is to write. I would give a very poor grade to a paper that said, "She danced well. She weighs too many pounds." Writing, like dance, requires creativity and imagination, and he found a creative way to say it. It was an ironic play on words. If he had made a reference to her aforementioned anorexia, then I would object. As it stands, I don't see anything wrong with what he did.