During the Pilot Dr. Foreman is 16 when he gets caught stealing cars, Marcus Foreman tells House that Dr. Foreman was 14 when they were caught.
(at around 48 mins) Lucas trips House and moves his leg back. It stays back while he says "Oh, I'm sorry, was my leg sticking out?". The subsequent shot shows him moving his leg out of the way again.
In the opening scene, Daryl's mother is sitting to the scout's right. When they cut back to them after Daryl rages out, she is on his left.
House says that the team may have to tell Daryl to retire at the age of 21 if he cannot stress his heart. However, the team earlier tells House that the patient is 22.
Normal sprinkler systems in domestic abodes are not rigged in such a way that all the sprinklers go off at once but only those in rooms where there is actually a fire. Otherwise, lots of property would be needlessly destroyed by water damage. Only high-risk facilities that might immediately go up in flames are rigged like that, such as fireworks factories.
The sprinklers however has been sabotaged by Lucas. They didn't go off as they normally would but to cause maximum damage and annoy House and Wilson as much as possible.