(at around 15 mins) Babberley puts his hat on the chair to the right of the door as he enters Jack's room. After hiding the stolen champagne in a case and making for the door he is met by Jack and Charley. When Jack puts his own hat on the same chair there is no sign of Babberley's.
In all Oxbridge (Oxford and Cambridge) colleges it is a strict rule that only fellows (and their attendant guests) are allowed to walk on the grass within the college grounds. However, in the film, students and others persistently ignore this regulation.
(at around 4 mins) The "Square Leg Umpire" is in the wrong position. Technically he is at "Backward Square Leg".