Really? A part of the Titanic story that was pure fiction, made up by Mr. Cameron for the movie. A study done saying that Jack and Rose couldn't have shared the door? A study of what, the script perhaps? Hell, he could have written the door bigger.
I know that many people love that movie and I even, to a small degree understand why, however, it is just a story about a massively tragic accident at sea that took over a 1000 lives. The story of the Titanic is not a love story, it is a tragedy of epic proportions. The story of the Titanic is shown in the movie titled "A Night to Remember". A 1942 movie that captured the real events in a way that was a lot less fiction and much more of a representation of that tragic night. It was the largest accidental, at sea, loss of life in history.