"Son#1 (my only son) was then invited to take urine and hair drug tests and passed with flying colors."
Pardon me, but from the tone of your post, why do I think that "invitation" was not voluntary?
Did he volunteer to take a test or did you compell him to do so?
Please do not misunderstand me here, I understand how betrayed you feel, but from both an ethical point of view and in terms of the basis of trust between you and your son that concerns me.
Drug tests are not voluntary inside my house. My son (17) and daughter (13) have known from the time they were old enough to understand that random drug screens would occur as a mater of business.
I have always told them (and followed thru) that if I test them, everyone in the house tests at the same time.
Sorry if that ruffles anyone's feathers, but I am basing that policy on the childhood I lived. Don't like it any way... Tough.