Ordinarily, “boiling down” (as described for this product) is associated with the making of gelatin. They do in the write-up of this product use the word “flesh,” but flesh includes all soft tissue.
Lacking an amino acid profile, one cannot say for sure… I can say only that I don’t know of a commercial (bulk materials, selling on a scale suitable to supplement companies) supplier that any supplement company could be buying from that produces beef protein isolate from meat. That doesn’t prove there can’t be one: if anyone knows of or can find such a commercial supplier, that would be good information.
There’s nothing wrong with having some collagen hydrolysate as a very small fraction of the total protein intake, but in and of itself, it’s not of high biological value.