I am in the construction industry and know how these things work.
Having said that there are always two sides to every story and we have only heard one side on here and without been judgemental or prejudiced this could be biased.
It has been mentioned in the thread that the son was 'made' to go self employed, from my point of view at least an opportunity of further work was given, especially in this current climate.
Curiously a good tradesman in my opinion would not suddenly be 'got rid of'....so how big were these mistakes 'which the boss told him to do'????