I think the Thursday night on Truth around Skindred last year was definitely another example of crowd crust being particularly bad. Our group had been at Truth, about halfway down, just in from the left hand wall, from about half seven onwards, and whilst it definitely got noticeably busier by the time Skindred came on it was never that bad, and being that side meant even popping to the loos near the Rocket Lounge was very manageable. I think by the sounds of it the problems came along the path at the back, and especially over the right hand side, as people came across the railway line from the Common and just stopped in a bit of a mass.
(Not saying there weren't issues, just that, as so often at Glasto, even in "the same" crowd, some parts were way worse than others)