It's still the Grammys... even the most seasoned performer would get nervous on a stage like that. I certainly didn't mind a few extra crotch shots during the performance.
The only real grievance I had is with Lady Gaga winning Dance/Electronica awards over people like David Guetta and The Crystal Method. She should have won something in the Pop category so that people who truly make Electronica can get the Grammy nods they deserve. That's more of a committee thing than anything else.