I am not sure what he was getting at...
That would only be true up to a point, as long as you yourself have the spiritual gift of pastor-teacher awaiting to be developed.
Then you could reach a point of not needing him to understand the Bible.
Even my pastor, who was considered a pastor's pastor and an excellent scholar, still studied the works of other men.
There are etymologists. They can teach others how to determine the meaning of certain words. But, that does
not make someone into a pastor-teacher who can teach the Bible. And, as a must, one also must become an avid student
of history. For, good Bible study requires being able to master isagogics. Isagogics is the discipline used to determine the
meaning of a word, or expression, found in the Bible to know how it was used at the time the Bible was written.
Just learning Hebrew and Greek [accurately] is a great accomplishment in itself. But it can leave one not knowing why the Greek said what it was saying... which in turn can open a pandora's box of speculations.
In the days of the formation of the church, people did not at one point leave a pastor to stay home to study for themselves.
Because a true pastor should always be growing, and his flock that follows will also continue to grow as he grows in grace and knowledge.