When there is a fire at the synagogue, the fireman are aiming the water hoses at one of the outside walls, nowhere near a window or door, therefore it wouldn't help contain or put out a fire.
Trivia: Judith looks gothed up after reappearing "head and shoulders only" through the door after talking to Joan. This is either a goof by the production staff or suggests that this is not Judith at all.
It's unavoidable from a real-life off-screen perspective, but...David Dorfman (Rocky) has clearly aged in a year and a half since the last time he appeared, and got some height. Do dead people get older and grow up in the afterlife?
The knitting Punk Girl God says she knitted her top... but it looks crocheted, not knitted. Wouldn't God know the difference?
Joan tells old lady God that a mistake she made was dropping a stitch and purling when she should have knitted, but she's not purling at all. Her scarf is being made in garter stitch, which is only knit stitches.
The Sims II was released in September 2004, at least in the "real" world. The fact that Luke is buying it as a new release makes no sense since it's (presumably) Spring 2005 or thereabouts on the show - this season started in September 2004. It's possible they're referring to Sims 2 University, which was released on March 1, 2005, but Luke and Friedman certainly talk to and refer to the game as if it's the original, not the expansion.
Big Tough Guy God says that in A Tale of Two Cities, Sidney Carton says "Tis a far, far better thing..." Actually, he thinks it - "If he had given an utterance to his [thoughts], and they were prophetic, they would have been these..." By definition, shouldn't God know the book perfectly?
When Joan is talking to Stevie at the end, Stevie's hair changes. It goes from in front of her face to behind her ear without her moving it.
You can't get into high school without your Social Security Number, so how is Stevie in school?
In the scene where Adam introduces Bonnie's work to Mrs. Girardi in the art room in school, there's an inconsistency. When the scene switches between Adam and Bonnie, Adam's sleeves are rolled up in certain shots and down in others.
When Joan walks into the park, Cub Scout God crosses behind her and goes off screen-left. But then he instantly appears on Joan's right and says "Hi, Joan!"
In the scene where Joan is talking to the T-Shirt Vendor God, God gives Joan the sticker on his shirt, but when he leaves, the sticker is back on his shirt.
In the scene during which Joan confesses to Helen that she went to the concert, some shots show 2 plates of cupcakes and other shots show only 1 plate.
Will is tossing pillows off the bed. He grabs two pillows, one in each hand. He throws one to the floor and holds on to the other one. The mirror shot shows him empty handed as he grabs for the pillow he just picked up.
When Andy comes into the DUI accident he says the accident occurred two years ago. Which contradicts various other episodes saying it's been either two-and-a-half or three years.
When Joan and Adam are in the camper in bed and Joan refused Adam for the first time of having sex, several different angle shots are made, where Joan's hair is hanging different. In shots from Joan's side, her hair is hanging over her back, in shots from Adam's side Joan's hair is hanging beside her face.
Luke and Friedman are making rap sounds in the hallway. Stevie comes around the corner. The camera goes round and then the camera shot is made with Luke and Friedman on the right side and Stevie in the middle. Watch the guy in the back playing with the elastics. The elastics springs in his face (acted or real?).
One of the brothers falls out of the door and over the railing onto a green trash can. This trash can just falls over but doesn't roll anywhere and two garbage bags are kicked. Later on in the scene the trash can and garbage bags have disappeared.
Not so much a nitpick as a missed opportunity. Byron and Shelley were not just famous poets, but social rebels who challenged authority and got involved in revolutions. If Substitute Teacher God had mentioned that part, Grace would probably have been a lot more interested.
When the power went out, Roger and Joan bring out five candles. At first they are spaced oddly, three in front of Roger very close together and then the two in front of Joan more widely spaced. A minute later we see the five candles all perfectly spaced. A minute more and we see them back with three close together and the other two spaced widely apart again.