What arguments could the SLOC members make that the payments made do not fit the payments made do not fit the definitions of illegal bribes under the FCPA?

Huh?

SLOC? Schenectady Light Opera Company? St. Louis Orienteering Club? Salt Lake Orthopaedic Clinic?

FCPA? Fairfax County Park Authority? Foreign Corrupt Practices Act? Fujitsu Computer Products of America?

They in fact do not have to prove they were anything,

The other side has to prove they were a bribe.