Factual error: Before the trip to Manchester, we see Charlie Hunham and Elijah Wood outside King's Cross station (London's station for trains to the North East & Scotland) with a GNER train in the background. In the next scene, they are shown inside Paddington station (London's station for trains to South Wales, Devon & Cornwall) catching a First Great Western train. The next scene shows a shot of a Silverlink County train, which run from London Euston to Northampton and Birmingham. In these three consecutive scenes we are shown 3 different trains, run by 3 different operators, none of which actually serve Manchester.
Continuity mistake: When in the Abbey, Bovver is on a table singing West Ham's team song. When everyone sings "Lets go F*ing mental" and starts throwing beer on Bovver his hair gets visibly wet. It cuts to another shot then back to Bovver whose hair is now dry. He is again doused in beer, then confronts Matt in the bathroom again with dry hair and clothing.