When Walter is leaving the lab to go in search of Bell, he puts on his coat, collar down. As he walks away from Astrid, the collar is up. When he turns to speak to her, the collar is again down.
When Olivia takes Jessica's phone back, the camera shows that the background of the iPhone's lock screen is Jessica's daughter. Before the camera zooms into the phone, there is the home page of the phone, not the lock screen. Also, the lock screen would normally have a panning highlight animation over the ''slide to unlock'' text. On this scene however, the highlight is frozen over the word unlock. Which reveals that the screen is actually a snapshot of a lock screen. Perhaps in order to delete the carrier name from the screen, which is also missing.
Walter states that it's a myth that if you drill straight through the earth from Boston, you will reach China. Instead, you will reach India. The antipode of Boston is in the Indian Ocean, 813 miles southwest of Perth, WA, Australia.