When Thomas arrives at the hardware store, he parks over one of the yellow lines. Later after he tells the store workers he wants to "launch them" (referring to the rabbits), the camera cuts to an outside shot of the Land Rover and it is now parked between the lines.
When Bea, carrying a box with a gift, first approaches Thomas McGregor, the wide shot shows the white gate shut, in the next shot it is wide open.
Just after Old McGregor passes away, his hand is shown closed as Peter pulls his ears free, but in the long shot immediately after it, his hand is shown as being wide open. It changes back to being closed when the shot changes again.
When Bea carrying a box with a gift ,first approaches Mr Thomas McGregor the wide shot shows the white gate shut,the next shot as she approaches the gate gate it is wide open.
The Sparrows that appear at the start and throughout the film are two separate species, one being a Tree Sparrow (who do not show sexual dimorphism and we can assume are possibly female from the voice) and the other being a female House Sparrow. This is odd having two separate species together and was most likely a factual error with someone thinking that a Tree Sparrow was in fact a male House Sparrow.
While the animals are hiding from McGregor, Peter tells the badger, "Just because you can't see him, doesn't mean he can't see you!"
Only the duck has seen the car pulling up in the driveway. Peter has no reason to know that it's a man who is going to enter the room. He may simply be using male pronouns to refer to the as yet unknown person as a matter of convention, as is still quite common in everyday language.
The workers that Thomas McGregor (Domhnall Gleeson) speaks to in the hardware store speak in very bad attempts at English accents, indicating that they were almost certainly Australian supporting actors (most of this film was filmed in Australia). The irony here is that Gleeson himself is an Irish but speaks in an impeccable south east English accent in the film.
When the Rabbits are hiding under the Land Rover at the shop, there is no rear axle housing. The Land Rover is 4WD and would have a rear differential housing. Just before the rabbits are revealed it can be seen that the rear axle housing is present. Yet when the rabbits are seen under the car, the housing disappears. Additionally, the shaft between the wheels should not spin because the axle shaft would normally be covered by the housing in a driven axle. The dead axle seen would only appear in something like a trailer, not a 4WD.
The Land Rover is carrying a red Jerry Can (petroluem spirit, or gas) in the rear behind the cab. It is embossed with AS2906, which is the Australian Standard code for fuel cans. In the UK it would be marked with BS 2869 instead.
Thomas McGregor departs London from Paddington Station when travelling to Windermere. Trains from Paddington head to South Wales and the West Country, so he should've used Euston, as that station caters for the North West.
The platform at Windermere Station is on the opposite side of the track to what it is in real life, indicating that it was a different station.
When Mr. Thomas McGregor opens the white door of his London apartment at No. 10, instead of British Locks, the outside of the door has an Australian Lockwood brand lock, and on the inside of the door is an Australian Lockwood 355 Double Cylinder Deadlock Deadbolt.
When Thomas McGregor is stopped on the road in the Land Rover due to the bonnet being up, it is obvious that the location is not in the UK. This can be seen in the style and location of the solid double lines; the lack of cats' eyes; the shape of the road sign; and the architectural style of the bridge.