Originally Posted by
FBinNY
Sometimes the best diagnostic tool is Occams Razor. Find the cause by eliminating things one at a time until there's only one possibility left.
I agree Occam's Razor is the best initial approach here, but what you cite is actually more like Sherlock Holmes - "When you have eliminated the impossible, whatever remains, however improbable, must be the truth."
Occam's Razor (the simplest explanation is the best one) would say that something about the adjustment the mechanic did is the cause of the problem. The diagnostic approach usually is Occam first, Sherlock next.
Even given that the hub cones are pitted, that does not mean it is the source of the vibration. In over 20 years I did not see a case where pitted cones cause the symptoms described.