Hmm, INT needs to be called when it happens, but it may take a second to register what happened, but then again, they can't consider what happened before it registered...This was the result of the play when it ended. Unfortunately, interference needs to be called when it happens. the umpire doesn't have the luxury of waiting to see what happens.
It seems as if this particular umpire did not handle it correctly, but then again, it could have taken a second for it to register that the runner kicked the ball.
From CPEM's description, it doesn't sound like a "quality throw" that has been stated as a requirement in other INT discussions.