What does the flat Earth model have to say to Moon terminator illusion?

The Moon's terminator doesn't always appear to line up with light coming from the Sun, i couldn't (fully) confirm this i  did saw a
crescent Moon once when the Sun is almost below the Horizon, the terminator doesn't really face the direction of the Sun sets.

This is a video from Vsauce explaining the Moon terminator illusion and explaining Crepuscular rays.