It is water under the bridge, but there were a couple principles I went by as a contractor:

I never worked for friends. I gave my advice free. I even gave of some of my labor to show them how to do things or bail them out when then screwed things up, but I never worked for money for friends. The whole relationship changes when money is involved. It is the surest way to sour a relationship.

Never pay for a project until you are completely sure the project is done and done satisfactorily. This is a lot easier to do when that contractor or worker is not a "friend". "Lord protect me from my friends, I can take care of my enemies myself!"