There appears to be a problem here. 450 g pork loin, 15% weight loss. That means the loin would have weighed 382.5 g after cooking. 450 g – 382.5 g = 67.5 g. 1 cup is 236 ml (US), or 250 ml (metric). 236 / 67.5 = 0.28. That's less than one-third of a cup, not a full cup.
800 g t-bone steak. Density of lean meat is around 0.96 g/ml, call it 1 g/ml for simplicity. 700 / 800 = 0.875. Around 85% weight loss? That is just about impossible.
I don't doubt that there was a lot of fluid in the bag. But, as presented, those figures appear impossible, unless water got into the bags. All that liquid cannot possibly have come out of the meat.