Continuity mistake: Near the start when Albert is plating up the takeaway, you see him beginning to remove the lid from the takeaway. In the next shot however, the lid is completely off. The change in shot is immediate and there is no way that Albert could have moved it in that time.
Plot hole: When all the gang including Arnie leave the flat to go to the restaurant to meet Mr Stavros, Rodney decides to stay at the flat and wait for Cassandra to phone him. The next scene shows the gang all watching Arnie in the restaurant waiting for Mr Stavros to arrive. Rodney is sat in the van with Uncle Albert but Rodney decided to stay at the flat so there was no way of him being there.
Continuity mistake: When Rodney and Cassandra are having their meal, pay attention to Rodney's beer. Whenever the camera shot is from behind Rodney, his beer has a reasonable head to it. But in the apparent instant that it changes to from behind Cassandra, the beer has absolutely no head whatsoever. This happens a couple of times.