I tend to liberally apply that old adage "never attribute to malice that which is adequately explained by stupidity," but HOW does a supposedly trained medical professional in the AIDS era NOT pick up somewhere along the way that you DON'T reuse needles?
He may be crazy, but I think he is either one of the laziest S.O.B.s ever born, or he was acting out of sheer malice.
Of course, I am not all-knowing all-seeing. I am just using a little common sense. I could be wrong.