When Lady Matilda shoots Dave Hicks' windshield, it leaves 8 holes, in a regular pattern of 4 groups of 2. When he gets into the car and drives away, there are still 8 holes, but now they are randomly distributed. When he arrives at Barnaby's, there are 12 holes.
The clock in the bus is inconsistent. While Mayor Hicks is welcoming the passengers just before the trip to Brighton, in subsequent shots the clock behind him changes back and forth between 12:20 and 8:05. And later, when Jenny Russell asks the passengers whether she should take her husband back, the clock says 12:30. But in the last quick shot before she sits down, the clock says 6:03.
As the coach is starting out for Brighton, the clock hanging above the street says 12:01. And yet they arrive in Brighton well before that time, because when they disembark Mayor Hicks says, "Remember, back on the coach by twelve o'clock for the short ride to the reception."