So, this is a little off topic, but I'm not sure that thsts the right read on the media environment. Everybody who hit front runner status went through a similar teardown period - even Biden, though I'd argue his was more genuinely damning han most (remember back in the dawn of time when he entered the race and all those "he's handy" pieces sprouted up? Enough to put me off him.) Then Warren hit frontrunner status, got blown up over M4a. Pete hit Iowa frontrunner status, wine cave debacle. Bernie, it's looking like his health. Its been the same thing all cycle.I get what you're saying, but it's not a secret why this didn't become a major concern for most news pundits until Bernie started doing very well in the polls and getting endorsements very recently. That's why I don't think that it's likely to affect anyone's perception of things, his supporters can see through stuff like that.
And it's definitely unfair, but I think it's a definitely a good thing as well in this case.
Up until now, I kinda think that being ignored has worked in his favor. Like I said, the focus a new frontrunner gets has rarely been positive, and it's given his team something to rally and fundraiser around. Besides, he didn't need the name ID like the smaller candidates did. I'm really not sure it hurt him.