I'm guessing there are non-zero number of people(not including myself) who hoped it is about a secretly reprogrammable mouse sensor.
Many cheap mouse sensors these days are ultra integrated to the point they often even lack USB pullup resistors. If they could be reprogrammed to, say, add a pixel dump command that very few of them implement, that would be very interesting.
This is about as "true" as fully replacing a Honda Civic's engine with something that has 10x the horsepower, and then advertising that you managed to get 10x the horsepower out of the Civic using the Civic's engine.
Your argument is more one of philosophy / law / BS than something anyone would take as true.
This doesn't even remotely address anything anyone has said regarding your claim about playing a game with the "mouse's firmware". At least you're now aware of how ridiculous it sounds, but clearly you don't care so long as you believe you could win this in some imaginary court case.
Well yeah, GP's argument applies here too: whatever engine you insert into your Honda Civic will be the Civic's engine, so the statement would be correct - as long as you specify that it's the Civic's engine and not the Civic engine (as in the original one).
To be less academic: I don't think there is a mouse in this world where you can actually modify the firmware, because using flash memory for something this dirt cheap and with a functionality that hasn't changed for decades is out of the question, so this is probably the only way to do it...
Many cheap mouse sensors these days are ultra integrated to the point they often even lack USB pullup resistors. If they could be reprogrammed to, say, add a pixel dump command that very few of them implement, that would be very interesting.