Yes, I think Liz didn't attend because she had to be on the set at 8:00 am on Monday. I'm assuming she was invited, of course.
I watched the panel too. It was fun.
Someone asked Damon/Carlton about the outrigger scene. Who Juliet and co. were shooting at. People will forever ask them about it.
Obviously, they didn't answer. They just said what has been said before. They wrote the scene, but decided to not include it on the show.