True. The Lennon Estate (and the Tolkien Estate, and others) are very protective.
In any case, when I create videos (and I've done a few), I don't use any elements of the video without clearing it with the original creator, first. (For instance, I created a video about the Gettysburg address, and found an image I wanted to use, but the copyright wasn't exactly clear. So, I emailed the original creator and asked for his blessing, which I received within a day or two).
Better safe than sorry, right?