There's a difference between eating your dead in a survival situation and consuming animal protein over an extended period of time. It's not that they're not capable of it. It's that their bofies aren't adapted to it and it's inefficient for them to process over long periods. Their bodies are adapted to process plants more efficiently so they do. If they're starving they'll eat what they can. Biologists have known this for a long time. This isn't new information. The differences in teeth and intestinal structure are very distinct. We've cutting open animals for a long time.

Obligate Herbivores will have extra stomachs and digestive chambers, special reguritating mechanisms to allow rechewing of food.

Obligate Carnivores tend to have shorter simpler digestive systems not capable of processing plant material.

If anything I would be more impressed to find out some carnivores were found relying on plants than the other way around. Plants are harder to digest than meat is. A herbivore occasionally eating meat really isn't that rare or anything to get excited about.

Discovering a tiger that lived on bamboo or something now that would be something new and would maybe be something we could use to start rewriting what we know about digestion.