Expert Beginner a.k.a "Sophomore" or the "wise fool"

Erik Dietrich has an excellent write-up of what he calls the "Expert Beginner."  As you read it, I'm sure you'll recognize the situation in a current or former organization. In the broadest terms, the academic phrase "sophomore" is well suited.

You can find it here: How Developers Stop Learning: Rise of the Expert Beginner

Another interesting post:  How to hire a senior developer

Using the definition provided by Wikipedia, would get:

The term is derived from Greek σόφισμα (sophisma), 'acquired skill, clever device, method', altered to resemble a compound of the Greek words σοφός (sophos), 'wise' and μωρός (moros), 'foolish, dull'.

reference:  https://en.wikipedia.org/wiki/Sophomore