It’s nothing to be surprised here. No one can boast universal knowledge if the Big Black Book of Protoss.
It is normal that X player knows something in more depth than Y player (even if Y is better than X generally).
Then Y gets some coaching from X.
Coaching is in specific fields, not teaching (a Pro-Player) how to play in general.
Case in point time ago KingCobra coached Harstem in CannonRushing. It does not follow that Cobra is a better player than Harstem.
One has to be BatZ-level of arrogant to believe that he knows everything and has nothing to learn from a player of the same race…