She weighed only about a hundred pounds, so it's possible someone could have thrown her over their shoulder and carried her there. They would have had to do it late at night though! Their clothes would have been dirty. I just don't think she was thrown over the cliff into the ravine. Yes animals could have scattered the remains, and... heavy rains also might move some of them down toward the bottom. Suicide is possible , but not likely. Again it depends on the knots in the leotard.
There's an article "Facts Elusive in Chandra Levy Investigation" posted today on the www.sacbee.com website. In it, Chief Ramsey is quoted as saying that her body was "found at the bottom underneath about a foot of underbrush and foliage.." indicating she was
placed, rather than rolled, there.
Also, turtleman's dog had to traverse the tributary (I believe that's the word used) in order to search the remains. More than interesting ... another dog to the rescue. By the way, the gentleman is not eligible for the reward .. the return was not "safe."