When Ben and Sarah get off the train they leave all their personal belongings (Ben's laptop, and Sarah's purse and luggage). Later, in the laundromat, Sarah's wallet gets stolen from her handbag, but she'd left all that on the train.
When Sarah is talking to her ex-husband in front of the bagel shop, the sky is supposedly very cloudy because of the storm, yet sunlight casts shadows on the street.
When Ben is dancing on the table at "Mr. Wonderful" his hands are alternately on his collar and by his side between shots.
Aircraft emergency oxygen systems or air masks are emergency equipment fitted to pressurized commercial aircraft, intended for use when the cabin pressurisation system has failed and the cabin altitude has climbed above a safe level. There is no reason why the compartments containing the oxygen masks would open when the airplane is still on the ground.
A flat vertical surface is needed to hear an echo; none are visible when they are atop the train shouting, and the trees around them would actually absorb the sound.
Trees are actually great for bouncing echoes.
Trees are actually great for bouncing echoes.
Reflected in Sarah's glasses.
Reflected in the window of the train when the kid is staring at Sarah from behind.
When Ben and Alan drive to a New York City airport, they arrive at Dulles Airport outside Washington, DC, which has unmistakable architecture.
The movie is supposed to start at one of the New York airports, but the terminal itself is clearly Washington Dulles, in Washington DC.
23 minutes into the movie they are having lunch outside. Behind them is the the Globe in Savannah. Anyone from Savannah will recognize it. Ben and Sarah are 1000 miles from Savannah.
Somehow, Vic managed to rent a car without a driver's license.