As the van pulls out of the hospital grounds, no traffic is passing in either direction, and the only traffic control is a small portable STOP sign at the guard's booth. But when the van enters the public road, it passes a long line of vehicles that have obviously been held up for the film production.
The open door is closed.
About half way through the movie their van is towed. We watch the first three feet of the tow and the rear side door is open. The film switches to another angle, shot with another camera, and the door is closed.
Jack claims that Leviticus 5:14 says: "Call not for a doctor, but an elder of the church," but the actual verse is: "The LORD spoke to Moses." The verse he quotes, or more or less paraphrases is James 5:14, which reads as follows: "Is any sick among you? let him call for the elders of the church; and let them pray over him, anointing him with oil in the name of the Lord."
In one early scene Christopher Lloyd, thinking he's a doctor, walks in on Stephen Furst who's singing the National Anthem while watching the start of a Yankees/Orioles baseball game. The hospital they're in is in New Jersey, and both the Yankees and Orioles play in the same time zone. But the clock on the back wall says 10:30. No games start at that time.