

Sure, but they don’t need to be proof of anything. Rossmann reported on some users (I think there were multiple?) claiming something to be the case, and provided one bit of verifiable evidence: no access to older firmware.
Brother claims they don’t intentionally brick printers that use third party cartridges, but that’s not verifiable. Brother also didn’t mention anything about why older firmware isn’t available. That’s a significant concern, since that would be a way for customers to prove that the firmware itself is the issue (printer works -> upgrade -> broken -> downgrade -> printer works).
I think it’s 100% fair to raise the concern. It’s certainly not enough to warrant any kind of legal action, but it is enough for customers to investigate the claims for themselves. I think that’s worthwhile.
But is it a lie?
Here’s what I’ve seen so far:
There’s still the claim about the older firmware. If it was available, it would be pretty easy for customers to prove that a change in the firmware caused issues w/ third-party cartridges:
That doesn’t prove it was intentional, it just proves it was the firmware update that caused the problem. If users want to stick w/ an older firmware, they should be allowed to, because Brother shouldn’t be able to decide what firmware they use.
The broader point here is certainly valid though, I’m just unconvinced that it’s applicable. Why should we trust Brother on this when they make the way to prove the issue nigh impossible?