Pilot Deviation - Legal Question

Scenario-

Crewed Part 135 jet is climbing out of XYZ airport. FO is talking to
ATC, and misunderstands a crossing altitude. Capt is Flying.

Crew subsequently busts altitude restriction. No close call/etc with
another airplane. ATC asks them to call XXX number, which they do.

Both crewmembers also file NASA form.

Few days later FSDO Inspector calls, tells Capt that "we need to make
this as painless as possible, its my job to follow up, etc, etc, could
you give me a written statement"

what to do?

I recommended that the Capt call AOPA legal or other aviation lawyer
just to present the situation to him

Capt (good friend of mine) said the FSDO inspector was "real nice to
me" and that "he is a pilot too"

comments?

(my opinion is that a phone call to a aviation lawyer should still
take place)