Slave Island - S1-E7
Plot hole: After Storm's attempt to escape the Genoshan prison is thwarted, she ends up in the ocean right at the shoreline of the beach, where she is captured by a Sentinel. Aside from the fact that it makes no sense for a Sentinel to be hiding in the ocean in the event that a mutant tries to escape the prison, there is absolutely no way that a two-story tall robot could hide in the ocean right by the beach, as the water would be way too shallow. You can even see that the water level only goes up to the Sentinel's ankle area when it is standing upright in the ocean. (00:03:15)
Suggested correction: Perception. (1) The Sentinel isn't as close as it appears. If it were close, then she would have been caught in its waves as it emerges. Also, she would be looking only at its chest circle. It's several yards away. (2) She washes ashore. She fell from the sky. She couldn't have fallen from that great height into shallow water without hitting bottom. (3) It's also a two-story tall robot. Its weight would sink it into the sand. So it could have very well been down that deep.
Sentinel never sank into sand in other episodes.
Well, it's shown here.
Character mistake: When wondering how close they are to the top of the cliff, Xavier asks Magneto "How much further?" The word "further" is used for non-measurable or figurative advancement. He should have asked how much farther, as that refers to actual distance between objects. An educated man like Xavier would certainly know the difference between the two. (00:02:44)
Suggested correction: While "farther" is used for physical distance, further can be too, especially in British English. Farther also tends to be used for a measured physical distance, so if the actual distance isn't known, further can be used. What Charles said is grammatically correct.