You have a strict cancellation policy, so your guest's observations are correct.
After he cancels, you will get a prompt from airbnb to refund a higher amount. At least it used to be like that - I have only had 1 cancellation under the strict policy in my entire career. airbnb service fees will not be refunded, so make sure you do not refund more than what airbnb says is maximum or you will be out of pocket.