USAF could be help or hindrance
I'm torn. On the one hand, there are some real experts in this sort of thing in the USAF, and they could be helpful. OTOH, there are also some overrated desk jockeys and bean counters who could be depended on to stall the investigation for years. And the USAF brass has shown great willingness to lobby, intervene or sandbag in favor of their buddies at ULA.
It is telling to see which politicians are on which side. Those asking for federal involvement are largely already in the ULA pocket. Certainly if the politicians were able to get an 'investigation' going, it will take a year or two before they even get started, and in the meantime SpaceX launches will be halted, decimating their market and forcing their customers to other competitors.
With the decades-long history of bribery, political manipulation (in the US and other governments around the world), and chicanery, it is not outside the realm of possibility that ULA or its parents Boeing and Lockheed might have had something to do with this call for an investigation. I strongly doubt actual sabotage, but I have fairly knowledgeable friends who suspected that from the beginning.