This is not an accusation - just a theory of what a reseller of mining equipment might do to maximize profit.
Did they ever promise to not "burn in" their equipment against the live network?
If they are first, they possibly will have the technical ability to perform a 51% attack. If they are in it for the long haul, they know that faith in bitcoin as a currency outweighs any short term advantage to mining where they reach 51% themselves. So that is your upper bound. At least starting out -- so they might mine using a dozen SC mini rigs until that difficulty adjustment rise is reached and then ship them out and work on the next batch. That way they've never exceeded 51% themselves, the network is stronger when they are done, yet they made some nice revenue from the testing.
They may not be the first and/or only ASIC to be producing from a working design.