Yes, it was Greg, in a cruddy t-shirt, jeans, and hair striaght up (more than usual) as though he had just rolled out of bed. Warick gives him advice on being prepared so Grissom will let him work in the field again.
Looks like the writers are building up to Sarah having a drinking problem, as she was acting strangely and popping cough drops to cover herself. You probably saw her heart to heart later in the show with Lt. Brass where she mentioned having a couple of beers at breakfast.