Here's the actual rule.
"Rule 4.03(a) states "The catcher shall station himself directly back of the plate. He may leave his position at any time to catch a pitch or make a play except that when the batter is being given an intentional base on balls, the catcher must stand with both feet within the lines of the catcher's box until the ball leaves the pitcher's hand. PENALTY: Balk.A "catcher's balk" is charged to the pitcher (for pitching when the catcher is out of the box), and has the same penalty as any other balk -- the runners advance one base."
You may be correct, if Barrera is in the box before the pitch it might not be a catcher's balk based on the wording of that rule. I still question if Barrera actually crosses home until he attempts to make the tag. I've honestly never seen a play like this in real life. If Barrera crosses the plate though and a catcher's balk isn't called, I'm guessing that's automatically considered a ball?