Ultimately I was not chosen for the role and I respect the decision.
I am here to offer constructive feedback on the disposition process, as I am a professional in the same field. When a person spends an extended period with you getting to know your company (a candidate, business prospect, employee etc.), and there are multiple face-to-face conversations the least you can do is send them an email (from you, not an automated email) letting them know that they weren't selected.