I agree. It is quite possible that would be the case. It's the 'finding' that is so frustrating.
I suspect my seller had acquired it that way and decided to unload some on e-bay. I was in no position to argue - I didn't have any contacts in the field.
It reminds me of Plus-X and Tri-X somehow. Not exactly like either but somehow the same. A bit more contrasty than I'm used to. I'm of the old school (60 years) and I like some more greys.
OTOH it's a perfectly fine film, used with HC-110. I'm quite happy to keep it. I even tried it with FX-2 successfully.
Know nothing about the colour surveillance film.