While there is some truth to that the pole had a near constant stable return during its tests, and the crow poo might have affected the ferrule based paints electrostatics I don't think unless the crows (via laxatives,) shat themselves to death over most of the test plane that the resulting reflections would be much different usual from surface skin bumps, dents, imperections and chipped and worn paints etc..
I think that snippet could hide something else possibly more serious.
Then again, due to that, and secrecy, all 'stealths' are kept in over pressured enviromentally controlled hangers, so no weather, birds, cameramen, or kinky crew chiefs G/F's can cause such wear and tear and hence leave the satin blackish kites pooped upon.
The marketing and spin dept are at hand in many books, certainly when it comes to possesing something culturally akin to a 'sword of damocles', such as stealth now is for the USA - like the A-Bomb, the B29, B36 B-58 and Skybolt Trident was/were before.