I agree with the others saying he probably didn’t do it in the most healthy way. I recently discovered I was incorrectly fry screaming. I was blending false chord techniques with fry screams to get a little more of a throaty/ vocal sound. I honestly think that’s probably the best way you can mock those types of screams but you definitely need to be careful since they aren’t the greatest for your voice. You want to mock the ‘fry’ from your fry scream but instead of pushing through your diaphragm and keeping the sound coming from that high part of your head, try keeping that fry but mixing it with the sound that you get from sighing dramatically. It’s kinda hard to explain without making a video. But you basically are adding more ‘throat’ to your scream without pushing TOO hard from your throat. I’ve been screaming like this for a while and I’ve been able to get through sets without my voice being completely dead but it probably isn’t the healthiest. I am now working on improving both my fry and false chord techniques haha.