When Olivia is talking to Christopher on the beach the tear tracks on his cheeks change several times.
Olivia is 19 minutes late for her 10pm meeting with the boat. It is then stated in the hospital when speaking with Agent Broyles that Olivia has been there for an hour. However, as they have that discussion, the clock hanging from the ceiling shows 2.35 instead of 11.20 as it should be.
In this episode Ronald Reagan stars in the alternate universe version of Casablanca (1942). In an earlier episode Cary Grant is said to have starred.
When Peter's phone rings near the end, it makes the appropriate noise of a phone set to vibrate, resonating with the wooden surface it's laying on. However when Peter picks it up, the phone continues to make the same wooden vibrating sound, even though it now rests in his hand.
When Olivia and Henry first sit down in the diner, a flag for British Columbia can be seen in the background.