They didn't film an electron in motion. They filmed photon(s) (that interacted with the electron), which means that each photon that interacted with the electron changed it's state of motion. Which in turn means that at any moment, there was no certainty of where the electron actually was and in what state of motion - just pointers to where and how it was travelling at the time when a photon interacted it, with limited accuracy, and more importantly how the two interacted with each other.
Remember, Heisenberg's uncertainty principle says that it's impossible to know both momentum and position of a particle with arbitrary accuracy, and that when the accuracy of one increases, the accuracy of the other decreases... If the position is known with absolute certainty, there is no infromation whatsoever about the momentum of the particle, and vice versa. In most cases, there's some inaccuracy in both sectors, depending on the experiment/application.
I think the most significant thing about this is the technique to visualize/gather information of interactions happening in an atom during extremely short periods of time.
