That's an H-bridge
Are you referring to the driver in the video?
If so then no it isn't an H-bridge but just four tip120s driving each leg of a unipolar stepper.
Those tip120s sure must be pretty rugged since I did not use any flyback diodes.
the diodes provide protection for the other arm of the half-bridge
Yeah that's what I guessed when "complimentary" was used in the def.
Thanks