i question that.. please provide link.
i'm guessing the ref thought the defender touched the ball after it left the shooter's hands, in which case not traveling.
hard to definitively tell from the video if the defender touched it or not.
that said, there is an uncalled travel on almost every possession these days, and often multiple uncalled travels per possession.
and often by the same player on a single play.
the player takes a couple steps on the catch before dribbling, (travel), and travels again on the drive or pass coming off the dribble.
when ESPN fell in love with the dunk, the rule makers dumbed down ball handling rules so the better dunkers, who usually aren't the best ball handlers, could do their thing without being called for travel.
then the refs relaxed enforcement of the already relaxed traveling rules.
then the charge/foul circle under the basket, (worst rule in sports), took the worship of the dunk to another level.