What's wrong with the term? That's what it's called when you call in a professional from a certain field to come in and provide education to others. It's used in a lot of industries where continuing education is being provided. Kid was an SME in his field. I don't see it as a braggadocios thing, it's more of a factual thing. Just like if he were an Professional Engineer and some firm hired him to come in and teach a group of P.E.'s or EIT's about thermodynamics, or fracking, or maybe onsite waste water treatment, as examples. He would be considered the "Subject Matter Expert" or SME by the firm hiring him. It is what it is.