Watch a little of the first video on the Broncos Outside Zone:
Outside zone if off-tackle play...
Outside zone is designed to cut upfield at the LOS, not bounced outside.
Then scroll to the 0:21 mark:
RB: Read the helmet of the second down lineman outside the Center
(the SDE, in the play being discussed).
If his helmet goes inside
(not the case here), turn the ball upfield just to the outside of him.
If his helmet goes outside
(which is the case here), so and a so forth.
Foster should have made the cut inside, just as I've been saying.