My headaches and pain level from fibro and getting physical therapy MAKE me get dizzy, usually not room spinning.
BUT, I do get room spinning vertigo like he's getting. I highly suggest getting a thorough exam hopefully including a neurologist who will do many tests to rule out things.
If it is termed "benign positional vertigo", he can have an experienced Ear, Nose and Throat (ENT) doctor OR a physical therapist trained in it, do a maneuver called "Epley Maneuver" sometimes called HalPike Dix SP?
It moves the crystals in the ear canals back where they can go out of the system. May take a few times, like once a week for three or four weeks. It takes minutes, but will bring on the spinning IF the crystals are still there. I've had it several times and it's time again . .. I go this Wed. for a PT to do this Epley Maneuver to me.
My prayers are with him.