"He's an employee, not self-employed."

Is he a shareholder, then? For a passthrough entity?

Are you asking for this:

https://www.irs.gov/pub/irs-utl/am2010007.pdf

A "regular" employee would not benefit from this.

Have they got the full determination?

Here's the earlier discussion topic:

https://proconnect.intuit.com/community/lacerte-tax-discussions/discussion/balance-sheet-179d-credit...