One of the American ghost hunters (who proclaims to never having been to the UK or even to know where Wales is) mentions British TV program 'Antiques Roadshow' in a wisecrack.
In the instances where we see the gramophone playing a record of "In the Evening By The Moonlight", the needle appears to be playing from the centre of the record at the beginning of the song, whereas this would actually be the end - it should be played from the outside in.
When Annie was in her apartment prior to flying to Britain, it's clear her " apartment " was in Britain because the light switches and power sockets were of British design.
It is stated that there is no way out of the castle once the main door slams shut. However, when the team regroup (just after hearing Kirk's scream at 01:00:28) there is clearly a sign in the background pointing to the Fire Exit. By law, Fire Exits in the UK have to be able to be opened from the inside - they should have just followed the signs to escape.