Well at least the Switch doesn't explode like a Samsung.
It is still early days and it does appear to use a lithium ion battery like most of the battery fun and games devices we have seen these last few years. Many of those seem to be the result of dodgy charge management controllers and early word is the switch will output some power to other things (
https://www.macrumors.com/2017/03/02/nintendo-switch-usb-c-macbook-pro/ ), I will confess to not knowing if that is expected behaviour though.
Anyway mini lesson on industrial design and production as it seems such things would do well here
Sample batch testing.
The act of pulling out a random number, usually 1% or so for the batch sizes I imagine they are doing here, and testing them properly. General stats say if those samples pass the rest will be good enough that any failures can be easily handled by your returns department. Nobody paying consumer device prices will want to pay for what it could cost to do full testing and thus we will see the occasional report like this. This is normal, sucks for the person it happened to but it is what it is and is nothing to get worked up about.
Failed batches either go for further testing to see if things can be recovered or for recycling/disposal, however many times they vanish into thin air and provide us with the unofficial spares and repairs market.
Design failure.
If the cradle is too narrow and pinches the screen then that would be a design failure, if it expands a bit after heating up then it is a different kind of design failure. If the quality control at the cradle making factory/section let those a bit too narrow through, or switches became too fat, then see the batch stuff above, though it might also have been a case that the tolerances (you say between these values rather than exactly this value as exact is possible but very expensive) were not specified correctly and that is a design failure.
Manufacturing failures can also happen, though the persons at fault can vary here.
Screens. Different industries and vendors have different policies on stuck, dark or lit pixels, as well as the placement thereof (right in eyeline vs within 10% of the border or something). For a cheap device with no claims to accurate colours or anything like the switch it is not unheard of in the slightest for it to actually be quite a few before they act.
