Sorry but I think it is worse because he is buying it for someone else. We had the same thing, hence the stupid number of viewings. There is no emotional attachment for the person buying BUT that said, they know the daughter wants it which puts a lot of sway on it.
We had the daughter round with boyfriend to look at ours, and then second viewing. Started making offers but they were stupid ones. Then the parents who were actually buying it as investment property for daughter to rent came to view it and then the proper negotiations started.
Then surveyor, then parents back to see property with survey in their hands.
Then daughter rings just at point of very stressful exchange to talk through how everything works like the heating etc.
I totally lost it at that point, we hadn't even exchanged, this was the Tuesday, they wanted to be in on the Friday, I had removal men booked for Thursday and Friday and to top it all I had just been to my mother's funeral who was like my best friend.
Luckily I lost it at the poor estate agent who rang to book the viewing. We exchanged on the Wednesday at 4.45pm, we had an email written and ready to send at 4.50pm to the removal company to cancel them and the phone in my hand to confirm they had the email before 5pm cut off.
Then we lived in a hotel for 3 weeks whilst we waited to move into the dream house I am living in. I am surprised I am still sane or am I now so insane that I can no longer tell?
My advice, breathe, stay calm, any defects he comes up with tell him that that was taken into consideration when the property was valued. Good luck.