The files are just title.webm and titleb.webm.
However, a second bug occurred, in that loading the game would still play the title screen movie (although not visible, the audio would overlap).
I noticed that I had "Options and Load Game Video?" turned off, and the video doesn't show on the options and load game (but the video's audio still plays). I don't know if that's intended.
When I turned on "Options and Load Game Video?", the video shows on those screens, and it stops correctly. However, when I quit to title, there's 1 frame of the video at its last timeframe before it resets back to the beginning.
So that's another workaround to fix the issue. I'd rather the video not show on those screens, but at this point I'm just thankful it mostly works.