Just because someone is eating more cooked meat does not mean they are eating less other stuff. They could just be eating more food, cooked food and junk food, in general, and I would assume they would have poorer health because of it.
Well, if study after study shows that the higher the percentage of cooked meat in the diet, the higher the mortality-rate is, then, logically whatever's left out of a 100% total must be getting smaller, by comparison, as a percentage - and therefore is, increasingly, less likely to be a factor behind the mortality stakes, with increasing meat-consumption being the more likely factor. Plus, there's the issue of appetite - people eating lots of refined carbs generally have a much bigger appetite than those eating mainly (cooked) meats, because there's no "stop" feeling with refined carbs, so, those on junk-food diets involving lots of refined carbs and not much meat would eat far more than the mainly-meat-eaters.
I do find that a lot of WAPFers have real problems trying desperately to explain away the deleterious ill-health caused by (lightly-cooked) meat diets. They always cite things like trans-fats or refined sugars, but these are only a very tiny component of a (reasonably healthy) cooked diet by comparison to cooked meats, say, so are far less likely to be the cause behind the rising mortality than increasing cooked meat in the diet.
As regards lightly-cooked meat diets, I have to say that I have not been too impressed by the gurus of those diets. The Bear had(still has?) throat cancer, Stephen Byrnes died at 41, Dr Atkins died of coronary heart disease(which is a condition brought on by heat-created toxins such as AGEs), and Stefansson died of a stroke(also linked to AGEs)at the age of 82.
I quite agree that simply by following a lightly-cooked-meat-based diet and avoiding non-Palaeo foods like grains,legumes or dairy, one can avoid a certain range of conditions, but that still leaves a whole range of other conditions such as coronary heart disease etc. etc., which are directly linked to cooked-meat-consumption.
Lastly, my own experience showed me that merely lightly-cooking my meats and eating only wild or grassfed(this was well before going rawpalaeo) did nothing for my own previous conditions(just made things worse, if anything).