Bowling over the catcher

[eastdavis]

Brand new here so if this has been addressed recently, sorry.

At what level of baseball or in what circumstance is a runner allowed to bowl over a catcher with the ball? without the ball?

My son is a 13u catcher. Last year in a Triple Crown tournament he was bowled over twice in the same game by the same player while he had the ball and was waiting with the ball to make the tag. Not close to a bang-bang play either time. Fortunately he held on to the ball both times. Unfortunately the runner was congratulated both times by his coach/dad.