Plot hole: Parker gains access to the external room using a valid security card, they figure out the CEO's passcode which opens the burn room door...and yet the room inside is still protected by a swarm of lasers. Was the CEO supposed to dance through the laser sensors like Parker does every time he goes in?
Continuity mistake: In the final scene the camera switches between shots from the front and from the back repeatedly. Parker's arms are folded when shot from the back, and by her sides from the front (and vice versa).
Audio problem: When Hardison is talking to Carrey, just after he names his price ("30%"), there is a shot from a strange angle in which we hear Hardison talk while his mouth doesn't move at all.
Continuity mistake: 4.03 - The 15 Minutes Job. Parker gives the target her number on the napkin, tells the guy to call her and takes a drink. The way she holds the glass changes immediately.
Continuity mistake: When Hardison and Spencer meet up with the rest of the crew, Hardison's suit is completely dry, despite having been thrown into a swimming pool in the previous scene. His collar is even pressed and starched. (00:16:50)
Continuity mistake: When Sophie is "shot", the two gunmen duck down immediately. When we see the flashback later, neither of them duck. One gunman walks away, while the other is revealed to be Elliot, who looks down over the barrier at the crowd for a beat before leaving.
Plot hole: The team starts to break into the Pierson building from the roof. But how did they get to the roof? It seems to be a pretty high stand-alone building.
Suggested correction: This is a question, not a plot hole.
It's a plot hole phrased as a question, perfectly valid. Given there's no obvious answer it makes more sense to have it as a plot hole, otherwise it's a question which gets the answer "there's no answer, it's a plot hole" and then gets listed again as a mistake.
I disagree. Not knowing how a character got to a certain location doesn't constitute a plot hole. There are many reasonable explanations for them getting onto the roof. They're professional criminals, and one of them is a cat burglar.
Deliberate mistake: When filming the fake movie with Sophie playing the nun, many holes are made in the door, but when she slowly kneels to the ground, there isn't a hole behind her, so it seems like she's been miraculously saved. But as the scene continues, the nun starts to bleed and dies. Technically, they couldn't safely put a squib that close to her. (00:21:15)
Character mistake: Upon finding the Spanish flu virus missing, Hardison freaks out about it killing 50m people 100 years ago, saying it would be even more deadly today due to the higher population. There's no reason to think so - the death toll in 1918 was massively exacerbated by the aftermath of WWI. Not to mention today we have vaccines, plus most deaths then were actually caused by bacterial pneumonia, which today is easily treated with antibiotics.
The Snow Job - S1-E9
Continuity mistake: After the mark has seen the fake MRI, he's talking with Nate and Sophie in the hallway. Nate walks away to the back of the shot, but in an instant, he's right back behind the two of them, saying, "Whoa, Whoa."
Continuity mistake: At the beginning of the episode, the priest is mugged. As he's lying on the ground, his face looks fine, but in the hospital scene he has a huge gash on the right side of his forehead.
