How does Uncle Hoskins’ attempt to ride the horse into the river impact his relationship with Richard?

As a result of his telling Richard that he was going to drive the horse and buggy into the middle of the river, Uncle Hoskins lost Richard's trust. He never trusted him again.

I never trusted him after that. Whenever I saw his face the memory of my terror upon the river would come back, vivid and strong, and it stood as a barrier between us.