Obstruction?

[tarheelcoach]

Situation - NFHS game. Bottom 8, visitors up by one. R3, one out. Ground ball to SS, who throws home. Catcher blocks R3, THEN catches throw and tags runner out. Runner never got to home plate.
Now, this call went my team's way, so I'm certainly not complaining. But I thought it looked like obstruction, but when I came home and re-read the rules, I wasn't quite sure.
The rule states that obstruction is "when a runner is obstructed while advancing by a fielder who neither has the ball nor is attempting to make a play."
When is the catcher waiting for a throw attempting to make a play? The catcher definitely semed to have blocked, then caught, then tagged. If my perspective is right, should that have been obstruction?