The guy might be a Top Gun grad but even if his quotes were taken out of context he has made wildly speculative statements about an aircraft that no one in the public domain knows much about other than how it looks from amateur photos. As someone pointed out in another thread we know nothing about the engines, sensors or even the materials that the plane is made of, pretty basic stuff if you want to know if this plane is a Brewster Buffalo or a Mitsubishi Zero. To make the statements like he did put him in the dubious company of the village idiots of Air Power Australia who have declared US airpower instantly kaput with the appearance of this aircraft and Russia's T-50/PAK-FA.
There is a lot more in a fighter than looks, the professional aviators here know that, and to presume that this aircraft will have all sorts of capabilities based on the thinest of into is awfully premature and amateurish. If you read some of the better articles on this supposed prototype you will notice that several mention that China has yet to make a decent modern jet engine, one analyst even noted that the number of countries that can do that is smaller than the number that can make a nuke, the most capable engines that can power the prototype won't have the ubiquitous 'Made in China' on them. And that is only the start of it, China certainly has made some leaps but you have to remember that they have a very short track record in modern aircraft development and are still dependent on others, namely Russia, for many of the basics. But for some reason you don't see that sort of sobering analysis in the more alarmist articles or hear that from a former fighter pilot turned trader. There are scores of competent military analysts, aviators and aircraft designers that could give a much better analysis, shame on them for being too lazy or too stupid to find a better one.
I am not saying to discount the threat but to say that the sky is falling based on a few fanboy photos is just plain stupid. And just because this aircraft is a surprise to the public doesn't mean it is a surprise to everyone.