The failed misson was a launch contracted and paid for by DARPA under their FALCON program. Anytime there is a failure under a Government contract, the responsible agency is obligated to have a failure investigation. The Air Force also participated. If it had been 'in house' with SpaceX, they would have just been drinking their own bathwater. So, the Government had an independent investigation, implicitly investing taxpayer money in the devleopment of the Falcon I, and awarded a follow-on demonstration launch. I would surmise Falcon I is no longer purely a "privately developed" launch vehicle - there has now been substantial Government investment, although I haven't seen the value. Maybe that is part of how Elon can claim they will be "cash flow positive' this year.