So sorry to hear this - do those couple of hours with the machine help him a little at least? Did he try different masks, by any chance? I had a nasal mask initially, and eventually switched to nasal pillows before I started actually enjoying mine. Everyone's anatomy and way of sleeping are different, so there's often some trial and error necessary.

For example, a lot of people dislike nasal pillows cause they're much easier to rip out or have a leak for some. A lot of people seem to like nasal masks, while I hated mine with a passion, as even with the XL size, my (large) nose's bridge was rubbing against it and hurt quite a bit. Some people also seem to love their full-face masks - they tend to work better for mouth breathers and those sleeping on their backs.