Huh?
They don't set the price of a barrel of crude, but they DO set the wholesale price to the station, or in the case of company owned stations, the price at the pump.
Let's see, a ten cent reduction of price at the pump would be about a 3.5% reduction in profits, so they would have made "only" $6.5B profit instead of $10B. Or that $3.5B would pay for a new refinery.
Granted, I know I am oversimplifying the financials, but you get my point.