The Third Wheel Gets the Grace - S4-E1
Continuity mistake: The stack of shoe boxes beside Rosario changes from when she begins to explain that she's been stalling Karen to spend time with her, to when Karen gives Rosie her credit card and makes a mad dash. (00:15:25)
The Third Wheel Gets the Grace - S4-E1
Continuity mistake: When Grace is standing in Barney's holding piles of clothes, as she says "he cracked under the pressure" the positions of all the clothes she's holding changes between shots. (00:19:25)
Continuity mistake: After Kevin throws the contract paper down onto Will's desk, the items on Will's desk, and the contract itself, change position a few times in the following shots. (00:27:05)
Crouching Father, Hidden Husband - S4-E3
Continuity mistake: When Will is telling the story to Karen using the small bottles of tequila, scotch, gin and vodka, the bottles sometimes change position between shots without Will touching them. (00:46:30)
Crouching Father, Hidden Husband - S4-E3
Continuity mistake: When Grace says "Elliot is here with me," at the school dance, she puts her left hand onto her chest. In the next shot her arm is down by her side. (00:51:45)
Prison Blues - S4-E4
Continuity mistake: When Jack goes into the kitchen to pour a coffee, the amount of paper on the kitchen roll decreases. (01:02:55)
Prison Blues - S4-E4
Continuity mistake: When Karen gives her name to the police officer at the prison, the guard behind her opens the jail cell door twice. (01:03:15)
Prison Blues - S4-E4
Continuity mistake: When Grace is in the bath, the remote control swaps what side of the bath it's lying on, and then completely disappears. (01:17:45)
Prison Blues - S4-E4
Revealing mistake: When we see Grace rolling down the staircase, when she hits the wall, it gives in, like a cheap set wall. (01:22:10)
Loose Lips Sink Relationships - S4-E5
Continuity mistake: When Jack tells Karen to look away from the hand cream guy, a pair of trousers appears in her hands between shots. In following shots as well, the height of trousers piled on the table increases. (00:04:30)
Loose Lips Sink Relationships - S4-E5
Continuity mistake: Jack swaps schedules with Dorleen. Jack gets a yellow one, Dorleen gets a white one. Later when Jack takes the schedule from his pocket, to bribe Dorleen to give him friday off, the paper is white. (00:05:30)
Loose Lips Sink Relationships - S4-E5
Continuity mistake: When Jack is talking to Dorleen, the yellow schedule in his hands disappears between shots. (00:05:50)
Loose Lips Sink Relationships - S4-E5
Continuity mistake: After Will looks into the mirror, after he puts it down it changes position between shots. (00:06:30)
Loose Lips Sink Relationships - S4-E5
Continuity mistake: When Jack is licking an envelope closed, standing by a large vase of flowers, the flowers change arrangement between shots. The sunflowers vanish and the poppies change place. (00:09:20)
Continuity mistake: When Jack comes in the apartment, he has a fake mole on, that mysteriously disappears after Will leaves. (00:43:00)
Visible crew/equipment: In Grace's bedroom, when Will says "c'mere you" to Jack, Jack runs over, and then Will pushes him out of the door. However, as Jack is running to Will, you can see the boom mike above them. (00:48:00)
Continuity mistake: When Karen sits down at the table saying "I get alot of cold water coming at me real fast..." between shots the slide box on the table changes position. (00:55:25)
Continuity mistake: When Will and Grace are in the kitchen, Grace says "We'll have to agree to disagree" then she slices her pepper in half. In the next shot the pepper is whole again, and she halves it again in the next shot. (01:11:45)
Continuity mistake: When the gang are at Grace's mothers, Karen takes her pill whilst holding the bottle. In the next shot the bottle is out of her hand, on the side, and the cup she was holding has swapped hands. (00:12:15)
Continuity mistake: After Jack tells Mrs. Adler that Nathan dumped Grace, she walks over to Grace. Grace is holding a plate of finger foods, with sticks in them. The sticks and food change position between shots. (00:14:35)