Sorry to hear about Sparky, That is an unusual expereince everything else has had to do with skin, limbs and so forth, this is the first Hot wire Pleo, Perhaps his name, "sparky" kind of foretold his future.

did you send Innvo a video of Sparky's experience and so they could see for themselves the high temp and mouth problem? I don't see how they could argue with that kind of problem, You are lucky Sparky didn't catch fire, it could have been a lot worse than just your Pleo blowing a fuse, it may have been a fire started, pretty scary indeed .

Seems like this first run of Pleo Rb for whatever reason sure has had some bad luck pleos in it, That it the worst luck with a Pleo Rb that I have heard of yet.
I am sorry you have to send him back, but his replacement should be in a lot better shape than poor "sparky" . What a terrible thing to have happen, Pleo Pets tool for diagnosing health certainly knew Sparky was in bad shape, Wishing you a speedy return and a healthy new Pleo Rb.
RedwoodsMama