This isn't unlike Apple's insistence on Apple-branded RAM being used in their machines; if you're having Mac problems, and you have third-party RAM installed, AppleCare will tell you to take a hike.
In any event, recording when a third-party battery is used does not shield a manufacturer from liability. In fact, it will be excellent evidence for the Plaintiff that the manufacturer knew of the design defect, and failed to correct it. Furthermore, the manufacturer failed to adequately warn the consumer. Two counts lost by Panasonic.
Not true. Twice I've had Macs have issues and both had Crucial RAM. Each time I was asked to remove the RAM and re-verify the problem. Each time the problem persisted and was fixed by Apple.
I've never had this issue, and I've taken in two machines for service with non-Apple RAM.
Sure this sucks for the consumer, but Panasonic has to protect their brand somehow from the nefarious crappy batteries. If I were in charge, I'd opt for the big ugly sticker on the box and in twenty other places, that says using non-Panasonic batteries might cause explosions and if it does you're SOL, or something to that effect.