Factual error: Towards the end of the movie where they finally can get on the bus the bus scene has two mistakes. One is that it travels ilegally on the right hand side of the road at speed over some chevrons but more importantly as they are supposed to be in Tipperary, there is a bus stop sign which says "Dublin City Bus" which is a completely different bus service to the "Bus Eireann" service they get on.
Factual error: It's meant to be set at the end of February but it seems to be spring/summer throughout (the best bit being the picking of carrots while staying in the guest house - definitely not an early cropper in the UK, and I'm sure not different in Ireland).
Factual error: When they arrive at Dingle in the boat, Dingle has a large dock for fishing boats - so it would be ludicrous to be dropped on a beach.