Goofs

Sailors are shown wearing berets indoors. The British military do not wear headdress inside.

The Submarine Skrulls would not be able to launch an attack against the UN plane without following very specific processes and protocols. We see none of those procedures/drills being done. The Captain of the boat, the XO, and the Surface Warfare Officer would have to give their approvals and everyone in the submarines command centre would know what was happening.

Priscilla is seen walking through London Liverpool Street Station but the background Station Announcer is calling a train service that runs from London Waterloo.

Commodore Fairbanks would not have any radar or data equipment in his home. They would be in the command centre of Portsmouth Naval Base.

HMS Neptune is not a Submarine. It is the land establishment at HM Naval Base Clyde.

The interior of the submarine is very clearly the interior of a building. It looks nothing like a submarine.

The submarine tower shown in the background when the under cover Skrulls enter the base, does not match any RN submarine. It is also tiny compared to the Astute class submarines which are the closest match. The tower should be the height of three people at least, with the topmost section of the body showing as well.

When Commander Fairbanks was not real Commander Fairbanks and was a Skrull in commander shape, why would release Talos from the gunpoint to save Zachery, who was original Commander Fairbanks' son? The shape-shifted Skrull himself could have killed Talos, Fury and even Zachery. He might have thought to retain his cover in front of Zachery, but he should have known that if Talos and Fury have come to this point, they are not going to leave unless the mission to shoot down UN aircraft is aborted, in which case Gravik could have killed the shape-shifted Skrull.

Commodore Fairbanks would not have security at his home. Royal Navy senior Officers do not have personal security.

If he was a Flag Officer (Rear Admiral or higher,) he would be given a property in Short Row within Portsmouth Naval Base to use as his home or office/mess. There would not be security outside there either. Base security would be provided by MGS (MOD Guard Service) who would be at base gate entries.

Nick Fury claims that no one calls him Nick and that's how he knew that Bob was impersonating Talos. The next episode reveals that his wife Priscilla calls him Nick.