Even in the UK, I have been referred to staff channel when positioning off duty. Presumably because I had uniform and company ID. Should I have put them straight!?
I think it depends on the airport, it's geography, and if there are any local arrangements with regards to the dreaded "conformance".
Certainly were I work we have fairly recently received a routine reminder of the consequences of using Staff search when not on duty, and the consequences of using a Staff ID to gain access to air side when not on Duty ...and it's pretty much as 4468 as described....(FWIW last time I looked even our positioning crews ex-base are banned from using the Staff process)
If the FR guys have local agreements best of luck to them.