This is a terrible comparison, for one Brady has never had any off field issues of any significance ever, and has always been a stand up guy. Hernandez was anything but a stand up guy since college. One is believable when he speaks, the other has always had controversy looming around him. I'll let you decide which.
Furthermore, Kraft came out openly in defense of Brady, I don't recall him ever doing that with Hernandez. Kraft is no fool, he believes Brady when he speaks, because Brady has never given anyone any reason not too.
So to say Brady is capable of lying like Hernandez is just someone being totally asinine.