- There's a test pilot on staff at the base, but they're not qualified for the Lightning.
- There's a test that needs doing, which doesn't require a test pilot (unless something goes wrong).
- There's no qualified test pilot available for the test, so Holden decides to run the test with someone who knows how to move the plane down the runway, but not necessarily fly it.
Of course you're deviating from the proper process at this point, but isn't the obvious choice for this still the test pilot who isn't qualified for the Lightning, but at least flies fighter jets?
It seems like Holden thought it through - it wasn't spur of the moment. Did he ask the test pilot? If so, did they say "no"?