I don't think "Protein Poisoning" is of serious concern. The dietary guidelines people could find no suitable upper limit for protein. But I agree that it would be better to know more about these diets.

Importantly, I don't think many people would say that <45% carbs qualifies as "Low Carb". 20% or 26% carbs is a more typical threshold. For example: https://www.ncbi.nlm.nih.gov/books/NBK537084/ https://www.aafp.org/pubs/afp/issues/2006/0601/p1942.html

They also only followed metabolism for 7 days when it takes several weeks to adapt to low or high carb, so you kind of need to see what the markers look like at six weeks plus for this kind of study.

> there is no mention of what the fat and protein ratios were and only talked about carb only

Wonder if this came up during peer review (and if yes, what the justification was for not mentioning)

In otherwise healthy individuals, I don't think protein poisoning is due to high consumption of protein but low consumption of other macros.