The answers he provided made him sounds like undermining his job as a "fun work try-out experience" (obv not judging byhis coworkers), kinda like being there just out of curiosity. If I were him, a phD and still doubted for being underqualified, I'd say "My history as an academia allows me to connect better to broader sections/fields. I'm confident that this is helpful for the position I am filling in." Even tho that means other sections can ask for your cooperation like in this chapter xD.
This important esp. in job interviews