All the CRs are tested obviously, so they ship as working units.
You have read the guide and the safe use page, correct?
https://lowpowerlab.com/guide/currentranger/In your video I see a lot of equipment, and it's not clear how it's all connected. I see a power sypply, a DMM, and a scope. You are focusing on the PSU and scope, so that's no good sign right there. I assume the bench stuff is all earth grounded. If 2 of these are connected to the CR, it's game over.
The floating DMM is no problem at all since it's not earth grounded and hence no ground loops created through the CR.
If I see what I think I see, your PSU is feeding a bunch of current through the CR, into the scope's GND/probe. The probe might even get warm/hot. The CR can also get warm/hot or even smoke if you put enough current through it.
If at any time they are subjected to common earth ground between any of the input/output/USB/headers then it can and probably will be damaged. I have seen this a few times.
I try to include as much warning against this as I can (label, guide, emails, forum, etc).
Then from that point this type of thing will happen.
The SAMD can completely burn (depending how much current you short through it), or actually still work but act erratically, the touch pads not working anymore, or the readings be bogus.
From what I see I cannot estimate what has happened. So I can't say that's what happened. But if you do that just once and you don't realize it, it's already too late.
I am trying to find ways to make it more fail proof and limit the damage that could happen when folks might do that.