Well, the dude has some very valid points about the cockpit video being totally out of sync with the HUD.
It's very poor editing on the People's Daily part.
Yet, he himself has explained later that this is more or less like a propaganda piece that's just like what they do with "B-course graduation video, or UPT graduation video", "you just splice a bunch footage together to make it look cool, but it's not actually representative of anything in particular".
I reckon that he knew what this video is about from the start. I don't think an ex-pilot of F-18 would be totally ignorant about the PLAAF. I think he knew that this is a war game combat training where the J-10 pilots are mimicking the US air force acting as aggressor, and took personal offence to that. So he has to fight back with some venom, speaking of Nietzschean Ressentiment and Slave Morality.
To be honest, the Video didn't impress anyone. What was the point of even uploading such a video? . The Pilot was turning his head around and above searching for the other fighter jet in the whole video. Didn't even give the impression that the HUD or the Cockpit information display was in use. The PLAAF could have released a better Training Video. If they released it for publicity, they could have done much better.
Why is there a need for the PLAAF to impress anyone with a propaganda piece? Most of the potential adversaries of China are also trade partners of China and couldn't gain an upper hand against the PLAAF anyways. The only potential adversary that does have a stronger air force to China is the USA. If China put up an real impressive propaganda piece, it will alarm and alert the US public and US military, which will result in the US becoming more aggressive and in more of an urgent need to poke China in order to test out China's capabilities.
Right now, strategic ambiguity is still the best thing for China.