There was some discussion, not too long ago I think, about the differences between rendered tallow and cooked fat. IIRC, there was a stalemate but little evidence that showed if there truly was toxins present in tallow that aren't in raw animal fat. I just looked back and you posted a link about a study done about the toxins in the tallow
http://pubs.acs.org/doi/pdf/10.1021/jf00070a016?cookieSet=1
The intro and first couple of paragraphs were all that was freely available
Though there were at least 4 OCD's found, the tallow was heated to 155 C (311 F) far above what it is when made originally made. After 376 hours of heating 10% of the cholesterol had been oxidized. There is also no where to check what kind of tallow it was and how it was originally made which further complicates things. But if I'm reading the paragraphs correctly it seems this study would be inconclusive with regards to whether or not there are actualy toxins in the fat in pemmican.
On the contrary, the evidence is quite clear, that heat oxidises cholesterol. Of course, there are far more studies done on cooked animal fats, in general, with only a handful done on tallow(unsurprising as tallow is hardly eaten by anyone any more). The main point is, though, that fat is not some substance that remains magically unaffected by heat. Simply put, heating any food damages it and changes it in numerous ways, changing its texture, destroying enzymes, adding heat-created toxins etc. Merely rendering a fat isn't going to solve those problems.
Someone, in referring to the dangers of rendered fats, quoted from an online text:-
> "Furthermore, [in cancer] there is commonly a deterioration in the
> lipid (fat-related) composition of the cell walls that allows toxins
> to enter the cells, and prevents waste residue from being removed. The
> main cause of this deterioration is the habitual consumption of heated
> or oxidized fats, and a deficiency of omega-3 fatty acids as in fish
> oils and linseed oil [and, he should have added, in grassfed animal
> fat]."
taken from:-
http://www.health-science-spirit.com/cancer1-overview.html