I assume this is the section the inspector is talking about.
2. Ground Fault Protection:
a. Approved ground fault circuit protection shall be provided for all feeder and branch circuits below or extending into inundation level.
If that is the case this is not a GFCI requirement, this is a GFP requirement.
(EDIT: now rereading it I am not so sure what they really want :?)
If you were to install GFCI protection I think you would always be going back for a tripped feeder.
Here are the NEC definitions of both.
Ground-Fault Circuit Interrupter (GFCI). A device intended
for the protection of personnel that functions to deenergize
a circuit or portion thereof within an established
period of time when a current to ground exceeds the values
established for a Class A device.
FPN: Class A ground-fault circuit interrupters trip when
the current to ground is 6 mA or higher and do not trip
when the current to ground is less than 4 mA. For further
information, see UL 943, Standard for Ground-Fault Circuit
Interrupters.
Ground-Fault Protection of Equipment. A system intended
to provide protection of equipment from damaging
line-to-ground fault currents by operating to cause a disconnecting
means to open all ungrounded conductors of the
faulted circuit. This protection is provided at current levels
less than those required to protect conductors from damage
through the operation of a supply circuit overcurrent device.
Notice the parts I made red, people vs equipment.
GFP is less sensitive and often adjustable. Easy to get with larger breakers.
What brand and type panel is the circuit coming from?