Plot hole: When the bullies take revenge on Marty, they doctor the chemicals he is preparing so that they explode. The bullies were punished some time in the afternoon, judging by the sun in the very first shot. Their detention is at 4:30 in the afternoon. Somehow, they manage to acquire the necessary chemicals for the explosion within a couple of hours, even though they are stuck at school. In addition to this, they have no way of knowing what chemicals Marty is preparing, so even if they were able to get chemicals, they would not know which ones to get to destroy his experiment.
Plot hole: When Jeannie encounters Mr. Rooney at her house, she attacks him and calls the police. Later, the police pick her up for filing a false report. Why? Surely they would've seen signs of an intruder such as a dropped wallet on the floor and footprints in the mud right next to the house.
Suggested correction: Without knowledge of what happened when the police visited, it's impossible to call this a plot hole. It might be that the police knocked on the door, Jeannie answered and explained that by the time they got there the intruder had gone. She could have got angry at them like she did on the phone. Maybe they arrested her there and then, without entering the house or searching the grounds (for someone they'd just be told was no longer there). Who knows? Unlikely sure, but not impossible.
Plot hole: Chelsea says that when her deceased father gave her one of his paintings (now missing), he wrote an inscription to her on the back. She says she cannot prove that he actually did this other than he noted it in his journal and she does not know where the journal is. However, when Chelsea's father presented the painting to her on her 8th birthday, there were at least 100 adults present at her party who witnessed him giving her the painting, writing the inscription, and signing his name on the back of the canvas which was displayed to the guests. Any number of these people could be contacted and corroborate her claim.
Plot hole: Kelly is a friend of Jason's from LA and they have been seeing each other since he transferred to Seattle (he mentions 'the other day' she saw something at the pet store). Basically the one passion in life Jason has, is karate. Her brother is the US karate champion, and yet Jason didn't know that or even that he was from Seattle. That's absurd on several levels, since it implies that he wouldn't know her last name (then how did they stay in touch?) and they never ever talked about anything personal, because it's fairly obvious it would come up really easily.
