Just because SOME radars cannot detect stealth aircraft it does not immediately follow that NO radars can detect stealth aircraft.
http://aviationweek.com/defense/commentary-do-russian-radar-...
http://en.wikipedia.org/wiki/Stealth_aircraft#Limitations
http://en.wikipedia.org/wiki/Bistatic_radar
http://en.wikipedia.org/wiki/Passive_radar
http://en.wikipedia.org/wiki/Multistatic_radar
Provided that you're willing to invest a minute or so (I spent 5 min finding links) you can discover that in fact he does know what he's talking about. This is established science and not at all contentious.