Here is the difference, according to the CRC.
multifasciatus differ s with the following traits, a)with a dorsal coloration on the flanks in loisellei above the 1st lateral line, forms a pinkish silver vermiculate pattern that almost covers the yellowish dark background base color in adults, particularly stronger in the forehead.
B) loiselle has an oval, higher body vs a shallow body in multifasciatus.
In my own opinion.... , how does anyone know what they had (at any point in time) if they got it from a LFS?
Just because it was labeled one or the other?
Maybe if you got one from Rapps who knew the catch point, then yes, its probably right.
But just because a LFS labeled one Freddy? or one loiselle?
I've been to LFSs that listed Tilapia as grammodes, or any Parachromis as a Jaguar, etc etc, so I take any name on a LFS tag, (unless I.D.ed by an expert) with a grain of salt.