Besides the usual problems we've all seen with new players, today there was an obvious group of friends in CODG who knew to bring the skull to the face, BUT didn't know you need to deliver a deathblow to it and knock it into Acererak before skull disappears, so they were telling people not to hit it. By the time they went to attack it, it was too late. Couldn't convince them otherwise because they've "done this trial a few times already."
Besides this ridiculous scenario, there's the usual ones we seem to encounter that make pugging this worse than a coin toss. I suggested they watch some youtube videos and checked out a couple myself and realize they didn't properly explain it either.
This trial is ultimately just a big frustration for everyone.