The "Timbits" they are eating on the beach are just pieces of donut; Timbits are round donut holes.
On the jetty, the union representative offers Kathryn some donut holes from a box that is clearly labeled "Timbits" (meaning they came from the Canadian chain Tim Hortons). Although there are a few Tim Hortons locations in the USA, none is in Boston where the scene is supposedly set.
The helicopter recovering wreckage appears to be registered in Canada, as the registration begins with the letter C.
The buses seen in the London scenes were not London Routemasters, the only kind of bus used in London. The body shape is that of a provincial country bus as was the livery. London Routemasters are always *all* red, the buses in the film had a white stripe round the middle half way up, no Routemasters had those. However the taxis were traditional black London cabs alright.