Other mistake: As the Germans open fire on the British sailors in a life boat, there is a panning shot of the crew. In this shot, a hair (or scratch) that made its way onto the film itself is visible on screen. (00:27:20)
Continuity mistake: Just after unveiling the Nazi plates on the SS-33, there are 3 seamen wearing brown jackets next to the deck gun. When the shot changes there are 4. (00:25:00)
Visible crew/equipment: Just as the SS-33 sets off we see the crew on board say "all ahead two thirds". As they say this the camera moves behind a ladder resulting in a camera shadow on the ladder. (00:20:50)
Continuity mistake: During the mission briefing, the position of the Top Secret folder changes from the centre of the map to the side of the map between instant cuts. (00:23:30)
Continuity mistake: Tyler states he doesn't know what's going on to a few seamen and tells them to do their jobs. As the shot changes the seamen have all disappeared from the background. (00:14:50)
Continuity mistake: When Tyler is out on the deck, he has his hand raised. When the "boat secure" order is shouted it's now lowered and holding on to his glass. (00:12:10)
Answer: Technically he's not getting fired, but Dahlgren did not recommend Tyler for his own command, and he won't get a promotion without Dahlgren's recommendation. Therefore, Tyler's only choices are to keep being an executive officer (which is possible but not what he wants, not to mention Tyler feels betrayed by Dahlgren and isn't sure he wants to continue working with him), or leave the navy entirely.
Aerinah