During the bathroom sex scene, Gray's haircut changes several times while she exits the bath.
The number and position of the CDs remaining on the shelf (as Mattie chucks them to the floor) change between shots.
A plate Sam is holding in his right hand momentarily disappears, then reappears, in the scene at the peace garden dedication when Dennis tells Sam he is planning to move out.
During the bathroom sex scene, the position of the curtain continuously changes.
They use two models of green Subaru Legacy Outback as a single car. The first showing is a 1998 or 1999 with the hood scoop, but near the end, she is driving the same one throughout the show, along the PCH. But when she arrives at the house on the beach it is a 2000 or newer model, which is a different body style, and clearly no hood scoop.
No hospital delivers patients food uncovered like they did in this movie.
Fritz tells Gray that Grady's child was conceived "at a Halloween party," but when Gray first meets the child's mother she says the child will be "four next October." A child conceived on Halloween would be born near the end of July. It is also very possible that Fritz made up the conception date since most of the rest of that story was also incorrect.
This is not a goof. When Fritz tells Gray that the baby was conceived at Halloween, he was lying. It was the same conversation where he said that the kid was "7 or 8", when we later learn that the kid was actually 3 and the product of an ongoing affair and not a one-night stand at a Halloween party.
This is the 21st century -- what kind of young person would NOT be taking advantage of technology, such as automatic payments to his child's mother.