As a former catcher and a father of a current catcher..... What makes a person qualified to determine what "ordinary effort" is? Just because a parent has watched his kid play ball doesn't make him an official scorer! On a throw coming in to the catcher with a runner bearing down on him those throws are not the easiest to handle. Often they move at the bounce giving very little reaction time to a catcher. The hit dirt/grass edges and bounch, etc. Plus a catcher may rush the catch/tag knowing the runner has the jump. Errors on catchers are typically throw away plays, fastball is dropped or clips the glove or catcher tries to pick the ball instead of blocking allowing runners to advance. To hang an E on a catcher due to what YOU believe is an easy routine bounce isn't very objective. What if a single is hit to the outfield with a guy on third. Play at home runner rounds first. Catcher instead of trying to pick said bounced throw blocks the throw like a pitch to stop ball and throw out said runner going to second. In your mind you felt the catcher had a play at the runner coming home. Do you mark him as an error??
That is why I don't worry about score books kept by parents. Very few of them are familiar with the rules and, understandably, driven by emotions. May be hesitant to not give their child an E or a friend's child. I don't worry about any one else's kids errors but my own. I know what errors he may have made and will address with him at the proper time. He can pick behind the plate with the best of them. Some coaches yell "great pick". I yell...."Your not playing first base. BLOCK".
I am expect more from him and what may not be an error doesn't mean it is correct.