I don't whether that's true, but I did witness the naivete of the Sanders' organization (or lack thereof) at my State Senate District convention about two months ago. Granted, Sanders had won the Minnesota primary handily, but like so many other states, the delegate distribution process is a bit convoluted and we still sub-caucused for individual candidates at the Senate District convention. Perhaps it was because Sanders' had won the Minnesota primary decisively that his team thought it was "game over" and there was nothing more to do, but there was no real Sanders' organization at the convention to keep the younger, less experienced Sanders' delegates on task, which was to stick around for the sub-caucus process. A lot of the young Sanders' delegates to the convention thought they just had to show up, put their name in a hat and hope it was drawn (or become a delegate by texting it on their phone) when delegates to the State Convention were selected. Welllllllllllllllll, if you've ever been to a Democratic convention of any type, you should know you have to sit through about an hour of mind-numbing discussion of rules and process before the fun begins and a lot of the Sanders' delegates left. As it turned out, the sub-caucuses kind of looked like this: The really old folks (some of whom were former or still-practicing hippies) and the millenials were on one side of the room for Bernie and the Boomers and Xers were on the other side for HRC when the convention split into sub-caucuses. It was kind of hilarious for a few of us old hacks.
I imagine that the scene was similar in other states. I think we saw something like that in Nevada where a bunch of Sanders' folks showed up and didn't understand the process and got waxed. Folks can argue about whether or not the rules of the conventions are fair, but those rules were likely set at least a year ago (or longer in many cases) and Sanders' team never really bothered to read them or read them and thought "F*ck this, we'll storm the Bastille." For a bunch of community organizer types, they were woefully unorganized. Early in the campaign, I saw comparisons of the Sanders' movement to Obama's organization in 2008 but that was wishful thinking coming from some of the uber-progressive wing of the Democratic Party. The level of organization in the Sanders' campaign wasn't even close to Obama's (at least from what I witnessed in Minnesota). Not even in the same galaxy. You can start as many revolutions as you want, but you're not going to win one if you arm your troops with water pistols.