Plot hole: The cable Emma dangles from is secured to a safe deposit box by a powerful electromagnet rigged up by Ash. When he turns off the power, which he will have to do (they can't leave the cable and magnets in place!), the whole rig will drop to the floor, setting off the alarms. Even under tension, it would be impossible to wind in the cable and magnet fast enough to stop it dropping, and there is no sign of any sort of mechanism that would allow them to try to do that anyway.
Hustle (2004)
1 plot hole in season 6
Starring: Robert Vaughn, Robert Glenister, Adrian Lester, Rob Jarvis
Getting Even - S4-E3
Plot hole: At the end of the episode, having conned Veronica Powell out of £600,000 - the purchase price of the house and contents they sold her - Danny taunts her by telling her that they did nothing wrong, implying that she has no legal recourse to recovering her money. He's wrong. One of the gang, Billy Bond, bids against her in the auction for the house, boosting her bid from £220,000 to her final offer of £600,000. Bond has no money and no access to any, and no assets that could be realised to cover the bids he made, something that would be easy for a lawyer to prove. It's called shill bidding and it is very illegal indeed. Since Bond and Ash Morgan (who gave Powell false information during the auction, spurring her on to bid against Bond) are both standing next to Danny when he makes his announcement I find it hard to believe that a shrewd, hard-hearted businesswoman like her would not realise that she had been conned and would not get her lawyers and the police on the case on the spot.
Mickey 'Bricks' Stone: Albert, what the hell were you doing in a church today?
Albert Stroller: Gil Stewart died this afternoon. I was there at the end.
Mickey 'Bricks' Stone: Oh God, I'm so sorry Albert. You two were like brothers.
Albert Stroller: We worked Vegas together. That man was made for bright lights. Poor bastard - died of a stroke in a dental surgery.
Mickey 'Bricks' Stone: Well, someone should sue them.
Albert Stroller: Aye, he was pretending to be the dentist.
The Hustlers News of the Day - S3-E5
Trivia: In some versions of this episode the name of the newspaper the grifters con has been rather clumsily dubbed over as "The Weekend World" rather than the original "The Sunday World", which is a real newspaper.