250k/year domestic is a lot but doable. BNA-HNL is only 2 segments - it's more likely he's hitting multiple cities each week. 8 segments a week in paid F will get you 300k MQM (at least) - 500 MQM minimum * 8 = 4k MQM/week = 200k/year + 50% PAG bonus = 300k.
At 300k/year you're "only" looking at 30 years to hit 9M.