Plot hole: The FBI is looking for a "very tall" guy who has been identified as such by various witnesses and by their own expert due to the entry angle of a fatal bullet wound - 6'5" at least. They send Elena into a bar near the end of the show to meet the Albanian perp who when he arrives is barely average height.
Plot hole: The show starts with the Jupiter crashing into the planet... also the other Jupiter seems to have had problems landing on the unnamed planet... why? The Jupiters were fully capable of flying around the planet as we saw it in other moments. None of them were attacked by the robot, they are not escape pods. So why crash land into the planet? Also why get out of the ship just to be stranded on an icy hellhole? The space ship is waterproof, as we saw in another episode. So why get out just to have one person go in again and get trapped on ice? And that's just the tips of the iceberg, pun intended.
Plot hole: When Takashi is rescued by the other soldiers, he finds a piece of red fabric on him. He then has a flashback to the scene where that same piece of red fabric fell from Hong-pa's body whilst she was hanging beneath the tunnel and realises they are both the same piece. However, when this scene played out earlier, Takashi did not see this happen. He was on top of the bridge and was being held at gunpoint by Eugene, so he couldn't have seen the piece of fabric fall from her body. (00:46:10)
The Book of Blood: Chapter Two: The Perdi - S2-E6
Plot hole: When announcing the 14 deaths, they make a generic statement to the friends and family of everyone in the pods, without first telling the affected families directly?! There's no way this would be dealt with like that - not least as they all then seem shocked that the parents start a riot/panic about whether their children are dead or not. Anyone with half a brain cell would have seen that coming a mile off. Not to mention that later on we discover one of the parents STILL hasn't been told if his daughter's alive or not. If this was a coverup or otherwise secret they wouldn't have said anything - there's no reason to announce the deaths but not clarify who died.
Mondays Are for Murder - S2-E13
Plot hole: In an effort to keep Glenn's death as quiet as possible, Higgins hires a private pathologist to do an autopsy to see if there were any foreign substances or poisons in his system when he died. A few scenes later it is revealed that Glen was undergoing chemotherapy. How is it possible that the pathologist missed the cancer and the chemo treatment in his investigation? What he found was an excess of antacids.
Plot hole: In "The Conners" premier, Dan solely blames neighbor Marcy Bellinger for Roseanne's death after finding a bottle of opiates with Marcy's name on it. He only relents after Darlene shows him additional opiates that other people gave Roseanne and were hidden around the house. However, in the Season 10 reboot of "Roseanne", Dan had previously discovered and confronted Roseanne about her multiple opiate stashes, including one bottle with Marcy's name on it which he read aloud.
Plot hole: Cadmus sets a brain-controlled Connor loose in public, without apparently remotely considering the possibility that anything might go wrong. When he regains control all they've got is a few goons onsite armed with regular ammunition - what did they think that would achieve? They know exactly what he's capable of. Either have kryptonite ammo or don't bother having anyone there at all.
Grass on the Streets and Weeds on the Rooftops - S4-E10
Plot hole: Beth surprises Jamie in the act of disposing of his father's body at the train station. But Beth doesn't learn about the train station until season 5, episode 8. So, how did she know where to catch Jamie in the act?