This isn't something you can just trivially unit test. If you don't see this happen multiple times during initial hardware development, you are never catching it. A single failure of a prototype can easily be attributed to a manufacturing defect - especially if it was hand-soldered.
Once it's in the field replacing the 0.01% of units suffering from random issues under warranty is far cheaper than having an engineer spend weeks trying to diagnose every single weird failure mode. Unless it affects a number of units, it's just not worth the money. You have to consider that support doesn't get a "the LEDs stopped working when I unplugged the device immediately after flashing it" message, they just get "the LEDs don't work". Support scripts are made for horses, not zebras.
It does affect a number of units, that's the point, and it's serious enough that the brand image is suffering. Just google "elgato unreliable" - tons of results, and when the top result is a Reddit post in the official Elgato subreddit of all places literally titled "My elgato experience has left me with nothing but hate in my heart", all alarm sirens should go fucking off.
To top it off, Elgato used to be a German brand right out of Munich [1]. German products used to be noteworthy for top-notch engineering and reliability...
[1] https://www.reddit.com/r/elgato/comments/18k92zy/my_elgato_e...
You don't know what kind of pressures they are under to deliver.
I know of significant compromises in all the software I have written, and I would make hardware mistakes if I had taken the electronic engineer path. Sometimes we have to prioritize and I've never had an unlimited time budget on any project (not even my own).
Projects with no issues are mostly dead!
But in practice I’m constantly having to power cycle my key lights and having to restart the stream deck app on windows.
Their ring light, for instance, can't be manually turned off using the shoulder buttons. It can only be set to a low dim. Why not? Makes no sense.
Their FaceCam needs a high bandwidth usb 3.0 port all to itself. Won't reliably work over a hub. Why not? I mean, give it a low bandwith 720p mode or something.
The Mic has a headphone jack, sure, no problem, but why does it install 8 audio devices during the install? Only install what is needed!
Their USB capture cards have issues staying connected unless they are plugged directly into the laptop/desktop motherboard, and even then they flip out every few hours.
These issues have ensured that I won't buy any of their stuff. I've recreated an entire elgato stack that would have cost $500+ for like $90 in cheap chinesium crap and it works perfectly.