When Alex pushes Noah Banes into a stack of shelves, equipment is knocked to the floor and a leg is broken off the stack of shelves. The next shot shows the equipment is in different positions and there are another two legs broken off the shelves.
When going into Larry's waiting room, the shot before entering Alex's sleeves are pushed up, but when they switch angles his sleeves are down.
When Alex and Diana are talking about Alex's "rare disease" Diana has a pencil in her hair in her pony tail. Viewed from the front, the pencil is at an angle, with the lower end on her right side. But when viewed from behind, the pencil is perfectly horizontal.
At different times both Alex and Diana pick up a vial containing an egg from a liquid nitrogen container with their bare hands. Such containers are always handled with heavy gloves and metal tongs, because the extreme cold (-346ºF) would freeze the skin off of bare fingers.
Larry and Diana claim that the famous physician Edward Jenner tested the smallpox vaccine on himself. Actually, he first tested it on a boy named James Phipps.
When Diana is trying to sneak Alex into the hospital, his fat suit is visible through his shirt.
When Alex disembarks the flight and walks away from the boarding gate with Larry, very clearly you see it was a Newark-Orly flight but the film is set and was filmed in San Francisco.
When Alex and Larry argue about whether or not Alex should keep the baby, Larry is speaking but his lips aren't moving.