I fully admit my biases against buttigieg, as evidenced above, but I honestly can't fault the sanders campaign for putting out their statement
based on the information they had at the time (and who knows how correct it is, but they had every reason to believe their information was as good as whatever anyone else had at that point), they won or came very close. they were responsible during their speech, saying they "did very well" but not claiming victory. and then buttigieg, after everyone else has come out with the same type of "we think we did well" or "both teams played hard" speech, went full "MISSION ACCOMPLISHED" and just outright said he won.
if you're the sanders campaign, do you just... let him? you can't. it's very possible that you won, so you can't just let him go "nah it was me" and get away with it. you're essentially obliged at that point to at least say "we're... not sure that's true", and if you're doing that, you might as well show the evidence you have at the time. they made sure to point out that they thought it was a representative sample from all different types of districts, but also were very explicit in saying that it was only 40% of the total districts because that's what they had available at the time. it at least feels somewhat responsible - I think they were put in an unenviable position, and I think they at least did a somewhat ethical thing.
