Something is not quite right with the time. We attended a 7:00 show in Charlotte, NC the very next night on the 18th. We intentionally got to our seats late as we didn't care about seeing the opening band.
Metallica came on stage about 9:10-9:15....NOT 10:15. Both of these shows are the exact shows with the only difference being the setlist. We were leaving the arena around 11:20-11:25.
You can validate what I'm saying at Metallica.com.....search tours and you will see all timeframes in pictures, videos, etc.
As for drugs, security was even banning ALL cigarette smoke in the arena and we only smelled pot once, for a VERY brief time. Like the other poster, other concerts where lots of alcohol was consumed/sold were MUCH more boisterous/wild. There were police, security everywhere and I do mean everywhere in the arena and I would assume it was the same in Charlottesville, maybe even more so since this is a college town/campus,etc.