So glad to hear this. This is still a Traumatic Brain Injury (TBI), but they have come so far in dealing with treatment and rehab for these injuries.
Hopefully, if he does go back to riding a bike, he will do so with proper protective gear.\
I rode horses up until a couple of years ago and I always wore a helmet. Long before it was a "given". I still managed to scramble my brains in my early twenties, but I think I've recovered from that.
I am sort of neutral when it comes to motorcycles. I agree that they should be able to share the roads, but I also believe that protective gear should be mandated.
That soapbox bit aside, let's hope Rob continues to recover well and quickly.