Australia routinely rejects people if it's thought they'll be a burden on the medical system.
If he hadn’t applied for the visa at that time, it’s almost certain he wouldn’t have caught it and wouldn’t be alive today.
He had no trouble getting approved for the visa - we were sponsoring him so we had already signed an agreement saying that we would pay for any government benefits he might receive over the next 10 years. So I don’t think people in this particular visa situation can be a burden on the system.
But this might not be how every visa in Australia works, I’ve got no experience beyond that.