Firm control in the air. Both feet down inbounds in the end zone. Control maintained long enough to take additional steps (football move). Catch is complete — he is a runner.
Under Rule 4-1-3, the ball is DEAD the moment a ball carrier goes out of bounds. The punch that knocks the ball free happens AFTER the ball is already DEAD. It cannot make the pass incomplete.
This should have been a touchdown. The call was wrong.