Gravity Is Overlooked
There were quite a few tricks that Cameron had to use in order to make the sinking of the ship look both realistic and intimidating enough for the audience. One of these camera tricks, however, caused this weird mistake to occur.
You can clearly see that the ship is slanted to one side, but the lifeboat that hangs from the side of it remains perfectly balanced. That’s not quite how gravity works, so it didn’t end up looking very realistic.