“A prestigious scholar can still have methodological problems.”

Prestige does not logically guarantee correctness.

Suppose Professor X is extremely famous.

They publish:

“Economic growth increased because of Policy X.”

But their dataset contains a serious sampling error.

Then:

Professor X's reputation does not make the methodology sound.

The methodological problem exists independently of the scholar's prestige.

This is why good scholarship ideally evaluates:

evidence and reasoning

rather than:

status of the person making the claim.