When Neil Jenkins is telling his story, he puts a towel around his wife's shoulders before the flashback of handing over the key, but then when the flashback is over, his wife has no towel on and he does the same thing again.
When Fredddie unlocks the door to John Green's room with a key card for DI Humphrey and DS Cassell they talk for a period of time that exceeds the time a key card will release the lock.