You should absolutely get a ticket for accidently driving over the speed limit, as the company should too. Its about safety and awareness. If you are not paying attention to the road signs and/or your cars speed, who knows what else you are not aware of. Maybe a child crossing the road in front of you.
Should you get a ticket for accidentally driving over the speed limit because your speedometer was broken? Should the company who made the speedometer get the ticket? What if the speedometer was broken due to a bug software the speedometer company bought? Should that company get the ticket?
Not a lawyer, but I'm pretty sure the burden is on the consumer in the USA to have their speedometer calibrated appropriately (10% error in the few states I've checked), and not doing so violates additional laws. Details could get complicated if you had proof that you did your part (OTA updates, can they prove you drove by a speed sign and should have known the speedometer was broken, ...), but you might be able to argue your innocence and might have a civil claim against one or more parties who touched your car.
