The guy obviously has some legit contacts and has been in the business for decades, what's not to trust about him that there are about others? If I had to put my trust on anyone, it'd be him by a long shot (which I do, I'm a subscriber~!).
If it was Vince's decision, smart call. If Undertaker really couldn't go any longer, why not give the streak to someone like Lesnar? The guy was losing his attraction appeal quick (and that's mainly because of their absolutely shite booking for him), this gave him it back. Plus, it just adds something else for Heyman to brag about.