Should I always follow blood runs thicker than water

my father was set up by my uncle. One day my uncle told my father to help him with some work. When my father arrived he found a company car in a ditch and called his about it his boss asked him what happened . My dad said he just got here and told his boss that my uncle asked for help but my uncle said that he has no idea what my father was talking about and basically pinned the blame on my father . My father just kinda forgiven him since his boss said to make sure this won't happen again but I honestly don't think I can really ever forgive him because my dad could have been in trouble.