I grew up right next to Wright Patterson AFB in Dayton, Oh.
We used to look forward to the booms over our houses.
At that time I believe they were restricted on the minimum altitude they could break sound barrier, so as not to blow out windows and such.
After reading the excerpt, I wonder if the jets were flying lower than the jets making sonic booms when I was a kid.
B52s and KC135s rarely make sonic booms ...