The chef had apparently not removed its nerves. He was supposed to.
スシローの悲劇 pic.twitter.com/DDLhXuuP0l— ブッチー (@shoumizo3446) February 11, 2018
We can't speak Japanese, but we're told the man isn't going "OMFG what the hell is this? Please take it away before I barf all over the place."
He instead something like, "yum! Delicious!".... or something roughly translated to that.