Of course it is the right decision and it's not even a case of conflicting right but of entirely different rights.
Everyone has the right to sex and sexuality, it's the right to control your own body and sexuality without fear of discrimination or coercion. Disabled people have the same right to sex as others, and an institution, doctor or carer cannot prevent someone from exercising their right to sex. The right is, rightly, established in many legal codes after years of abuses when certain people and certain groups of people, which have included the disabled, black people, ethnic minorities, gays and lesbians, have been targeted and prevented from exercising their right through criminalisation, sterilisation and castration.
The right to sex is entirely different from how one chooses to exercise this right. If this man, or anyone else chooses to exercise this right wrongly, e.g. abusively, without consent, etc. then they can be held accountable for this action. No one else is held accountable for what they might do, why should this person be? And how about others who may have already proven they cannot exercise the right to sex responsibly and respectfully of others, like rapists and paedophiles, should they be incarcerated for life or castrated? Why single out this person and not everyone who might act without obtaining consent?