He saw the play developing sure, but I don't he expected for it to be a free drive. Grayson didn't make any physical contact on the DHO and just let him turn the corner with no bump or resistance. He does any of that and Bradley is there in time.
And again, every Jazz player has been dunked on in similar positions because of bad perimeter D. Gobert has been dunked on like that before because he's trying to guard two players at once and the primary point of attack defender hasnt done his job of staying connected to the ball handler to allow the time for him to rotate.