Just guessing here...  

Dave did one video where he (I think it was on the ferry flight from the completion center back to Utah) showed up at Whistling Diesel's (another YouTuber) compound for some hijinks in the Blackhawk. And I think that got him some scrutiny from the feds. In one of his subsequent videos, when it was obvious that he wasn't flying the Blackhawk anymore, Dave alluded to some issues he had with the FAA and the "paperwork"...after getting the thing home. Heh, "paperwork." It's fair to assume that what he thought he could do with that helicopter is at odds with what the FAA says you can do with an ex-military aircraft in the Experimental-Exhibition Category, as N801WT is. Putting it in that Category may have been a mistake. I bet he's looking for a buyer for it now. Because then he bought his two Standard Category Dauphins so he can fly around doing crazy Diesel Dave stuff. He's obviously a good, conscientious private pilot who makes entertaining, well-produced videos that generate a lot of money for him.  And he's obviously not afraid to spend money in aviation. What's not to like?