. Fat loss=energy deficit.Being in ketosis is irrelevant. You could easily take 200 calories from a palumbo diet for example than contains 1/2 cup cashews and replace it with 200 calories of rice and loose same amount of fat. Many studies show people in ketosis lost no more fat than people eating similar calorie levels. He probably just overate fat...very easy to get carried away with peanut butter for me.. 
my problem is on carb i dont stop once in low digits , i fuck my diet , i get carb addict n weight meal is annoying , keto , 300gr meat at grocery , never hungry , n dont slip ,, with carb i fail ,, fail contest diet ,, with carb i look bloated n watery ,, dieting on carb easy ,, dieting on carb til dry stage condition not evryone can do that ,, i cant ,,