Need clarification on obstruction call

[canadaump6]

Had this situation a few days ago. R3, 1 out. Fly ball to right field. As the right fielder is making the catch, the catcher stands on homeplate. R3 tags and runs home. The catcher gloves the throw from the right fielder, without changing his stance on home plate. Runner bumps into catcher and is tagged.

I ruled obstruction on the play because the catcher's position blocking home plate was the same from the time the right fielder caught the ball to the time when he tagged the runner. My partner later approached me and told me it was not obstruction because the catcher blocked the runner while in the act of catching the ball. He disagreed with my interpretation that the fielder's block of a base must be in the action of catching a throw, and cannot originate from a moment when he was not in the action of catching the throw. Was I right to call obstruction?