Other mistake: Whenever Charlie is playing the piano, it is clear he really is not. We hear notes playing that his hand is nowhere near at the time.
Last Chance to See Those Tattoos - S2-E11
Other mistake: When Jake says "hey dad check it out you can see my room on here" he says it before he has opened the webcam. Could be explained that he could see the program running on the taskbar but as is already listed it's not on the taskbar. (00:20:00)
That Old Hose Bag Is My Mother - S2-E22
Other mistake: When Charlie comes back on screen into the kitchen after looking for Alan, you can see him standing in the living room waiting to walk back on screen.
Dum Diddy Dum Diddy Doo - S5-E3
Other mistake: When Jake is sitting on the couch talking on the phone, he says out loud "we were on a train in a tunnel?" etc, Alan has not walked into the house yet, therefore could not hear Jake's phone conversation. However when Jake walks past Alan and continues talking on phone, Alan states "at least he isn't the tunnel." Alan was not inside at the time of this conversation, so it makes no sense that he would have heard Jake say this.
Answer: That would be "Corey's Been Dead For an Hour" in season 4, episode 9.
Super Grover ★