Runner coliding with Catcher While Fielding a Thrown Ball

[Atl Blue]

On a thrown ball, the runner must do something intentional to break up the throw in order to have interference. Bumping a catcher that is standing in the baseline doesn't even come close to an interference call.

Now, various leagues have rules regarding slide, attempt to get around, avoid contact, etc. Depending on the league, one of these rules MIGHT have come into play, but from the sound of your post, I doubt it.

But unless the runner did something you did not mention (i.e., put his hands up to pull down the catcher's glove, etc.), interference isn't even a possibility. Tell the coach to sit down and read a rulebook.