Thats a seprate issue to my question. I am not seeking questions to that concern here.
Look, Dad paid for it out of pocket, on his time, and it wasn't court ordered.
He doesn't need the results of a drug test to justify "restricting" the child - Dad is allowed to parent however he wishes during his parenting time.
Similarly, you are free to parent your way during your parenting time.
I am not seeing a legal issue here. I am seeing a power struggle between parents.