This is a different approach to making raw cat food. It's a bit like going to the grocery store and buying some extra items for your cat and then mixing them together. Normally, when we see raw cat food being produced at home we see large quantities being ground up and then stored, whereas this has the appearance of simply making a meal for your cat on a one-off basis so perhaps it is something that is easier to try if you fancied having a go at feeding your cat a meal that is completely different to what he/she is used to if he is fed a commercial diet.
Everything he says in the video appears to me to make sense. I will bet, however, that domestic cats fed a commercially made cat food diet may well struggle to adapt to this far more healthy and natural diet. Any changes in diet should be gradually introduced if the new diet is dramatically different to the former.
Although the domestic cat is an obligate carnivore, as this gentleman says, when the cat eats a mouse there is quite a lot of non-meat items in his diet such as the stomach contents and the fur. This is why this gentleman adds to the diet quite a lot of non-meat items.