5. The cold weather would affect the people while they were still on the ship
Jack and many people like him froze to death, because they were in the cold water. The cold and windy weather should have caused Hypothermia to everybody even before going in the water, so a lot of them should have died after being evacuated on the deck.
6. There was no discrimination for the third-class passengers.
Historian Tim Maltin said when the order for lowering the lifeboats was given, each door on the ship was opened and there was no class discrimination on the decks. Women and children were first, no matter which class they were. No one was locked underneath the decks.
7. British traditions instead American traditions
Titanic was a British ship, so the officers were supposed to respect British traditions. Will Murdoch, the first officer on the ship, before his suicide, gave an American salute instead of British as required.
8. Mismatch with Will Murdoch’s heroic actions.
In the real-life event, the first officer was loading up to ten lifeboats while the ship was sinking and helped a lot of people evacuate. In the movie, the actor shot 2 passengers who were fighting for free space on the lifeboat and then killed himself. This doesn’t seem heroic, does it?