Is someone diagnosed with Schzophrenia allowed to disagree with you?
Anyway. This moment is a _very_ direct test of this question. Answering it, or more carefully, your emotional reaction on reading this, will expose some of your absolutes.
my rule of thumb is that if the patient, after being returned to lucidity by meds, agrees in retrospect that meds were necessary, then it's the right call.
the other exception is if the person is at substantial risk of hurting others if unmedicated. then the violence of mandated medication is warranted.
barring that, if someone on psych meds wants to go back off them, I wouldn't prevent them from doing so.