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.
Plot hole: When Zach Young's grandfather died, Zach was said to be the sole heir of the fortune. However, Noah Taylor (the grandfather) had a daughter that appeared several times while Mike Delfino was looking for Deirdre. Where was Kendra Taylor while Zachary Young was spending Noah's fortune on dresses for Gabrielle Solis? Why didn't she claim her share? She simply disappeared.
Plot hole: The CSIs catch a murder suspect putting down a drink can when reviewing security footage of a robbery, and immediately realise they didn't see it at the scene so assume one of the first cops on the scene must have removed it. Thing is though, the murderers shot out the security camera before the actual shooting occurred, meaning there was loads of time off-camera for the killers to take the can with them, but the CSIs never even consider this - they jump to the conclusion a cop took it even though there's no actual evidence for that.
Plot hole: When Wilson does an ultrasound to check for cancer in Alex' ovaries he fails to notice the fact that she doesn't have a uterus. If he mistook her bladder for her uterus, which sometimes happens, she would have appeared to be missing her bladder instead. Yet Wilson doesn't pick up on anything being missing.
Plot hole: In the episode "Where's the Wizard?", when Pim gets the Wizard from Lil' Danny, she holds it in her hand. When Lil' Danny steals it, he takes it out of Pim's backpack, meaning it must be Pim's Wizard. But when Phil points it out, she says it's hers. This could be a character mistake, but if it was Phil's Wizard, they would not be able to track the one Hackett had, because inputting the signal of Phil's Wizard would do nothing.
Plot hole: In order for the show to be starting on "Day 1,412" as counted back from Cooper's eventual high school graduation, it would have to be a mere 49 days after his graduation from the eighth grade. (4*365 = 1460 + 1 for leap year) So it should be the middle of summer, but instead the school year seems to be in full swing. For example, it's already the end of Natalie's soccer season.
Plot hole: In the episode where Joey tells Jimmy that Michael is his son and they cut of some of his hair to do a DNA test, Gina tells Michael that he is missing some hair on the back of his head. In the next shot the angle changes, we can now see the back of Michael's head, and he's not missing any hair.
Plot hole: To escape from the students chasing after him, Damon jumps from a high ledge in the Duel Academy building and lands in the forest. Then he swings across vines at great speed, but somehow, the students all end up ahead of him in the forest, even though they were walking on foot. (00:05:30)