There is usually quire a significant deviation among production knives in edge angles, even if it is spec'ed at 20 you can find them from 15 to 25, so the spec angle isn't something you consider when sharpening but rather the angle on your specific knife. In that regard, the odds that the guy who sharpened it, adjusted it to be optimal for you is also near impossible as this depends on your skill level, physical ability and method of use.
-Cliff