Based on that set of axioms, it can be completely loving to encourage someone to repent of his sins and choose to follow Jesus. Practicing homosexuality is a sign that someone isn't doing that. It would therefore be unloving or even hateful to affirm homosexual relations.
He didn't "encourage someone to repent". He contributed money to an effort to institutionalize oppression in the law. His actions affected others, so those who disagree are entitled to do the same.