“The sound barrier was very real given the aerodynamics of aircraft at that time.”
It was an aerodynamic problem, not a physics problem. There was no law of physics that made the speed of sound a limiting speed. Bullets can break the sound barrier so we knew it was not some impossible wall to cross.
You are splitting hairs.
Is is more rational to believe that thousands of credible witnesses and instrument readings are mistaken, or that there might be something we don't know?