It's a bug in the processor that causes a bug in the software. It's not a bug in your idealized mathematical model, but try telling that to the people who paid you not to leak private keys.

I see my job as an engineer to be to create a product that satisfies the user's expectations (which in this case are eminently reasonable). It matters not one bit that I can point the finger to the chipmakers. I'm still selling something that I now learned doesn't do what I said it would. It's still on me to fix it the best I can. If I care about the product quality, that is.