I'm on my phone so maybe I missed something but I didn't even see that this was about exceptions to the rule? It seemed to be more about cases where the first sound couldn't be recovered orthographically. He special cased herb, for instance, because Americans inexplicably pronounce it "erb", or one and onerous because one is w and the other is on.

I can't think of a single true example to the real rule, it's an actually extraordinarily strong and simple rule as English goes.