modern reptiles in the 1 lb to 2,000 lb range may get by on fewer meals than modern warm blooded animals but nobody was around 67 million years ago so we can’t for sure say if that holds true for the T. rex as well. Still, it’s going to take a quite a lot of protein to initially reach 14,000 lbs and to then maintain it. I don’t think it would have passed up an easy meal whether it killed it,stole it, or found it.
Wasnt there a theory going round a bit ago that dinosaurs were actually warm blooded?