Actually he seems to know a lot more than your usual hack. I mean what average DIYer/handyman would know about crimp sleeves and proper tools to use them? Also you've got to give him credit for actually supplying a ground instead of suggesting anything illegal.
There is of course the issue of the non-GFI receptacle but is he in fact technically required to install a GFI if he didn't really change anything in the kitchen except for hooking up an extra ground?
Considering the age of the wiring I'm fairly sure that neither room is an addition but the house dates back to a time when grounds were required in kitchens but not in living rooms, bedrooms etc.
I love the beginning sequence... where he tells the viewer to never work receptacles hot -- because you could die -- and then proceeds to do just that.
I have noted that there is a propensity for those who know little to YouTube much.
As for my personal style, if I touch a receptacle that is as old as the kitchen device -- I replace it every time. (Modest price adder) I don't want to have to come back on a warranty call because I shook something loose in a marginal device. Likewise, I always expose fresh copper, or shine up old copper.
I wondered about the working hot part... it looked to me as though his touchless detector lit up a few times. That's stupid of course!
Replacing the old device makes a whole lot of sense in a contractor job where we're talking warranty but not really for a DIYer, which is who this video is aimed at. A DIYer only has to blame him/herself if the device fails a few weeks or months after s/he put it back into the wall.
Of course it is debatable whether DIY electrical instruction videos are acceptable at all, but if they do exist I prefer them to show at least decent work practice instead of shoddy or outright dangerous.
Electrically wise, the kitchen recept could of been protected up line by another gfci or breaker. I'm not a fan of grounding crimp connectors because I find too many old ones that are loose. The ding dong needs to learn to use a level and fine someone that knows how to mud. My blind grandmother can do a better job mudding.
Also grounding screws are 10/32 unless you are using Canadian Wiremold boxes. also he siding show how he pig-tailed the two old groundless cables to tie on the two new recepts
He made no mention of the missing deadfront on the panel, which appears to have been missing for some time.
He broke out the chisel, instead of trying to free the recp by wiggling the bottom of the yoke, and caused the beginning of the plaster damage.
Despite describing every other step in detail, he just jumped to the box being removed. It looks like he took it out with a hammer. More plaster damage. If he had used a sawzall with a fine metal cutting blade, there would be much less damage.
He twists the grounds together incessantly & needlessly.
Didn't even mention the need for GFCIs in the kitchen.
Most houses of that era (late 50's to early 60's) have a #16 ground run in the romex to the circuits that need grounding. (I believe the video maker is in CA, from the looks of the service). That might not be the best choice of houses to make a how to video.
The patching plaster is still shiny wet when he called the job finished. No sanding necessary