Washington had a caucus for delegate allocation which Bernie won with more than 70%. And all the neighbouring states went to Bernie comfortably with Seattle having one of the highest per capita donation.
What are you even talking about? Real ballots went out, and real people voted in that primary. Yes, Bernie overwhelmingly won the caucus, but that is because he had the most enthusiastic base of the two. That is who wins caucuses - the candidate with very fired up & enthusiastic support, and it's also the reason they are a terrible way to choose candidates. It allows a candidate with well below majority
(or even plurality) support to win a caucus simply because they had enough people willing to sit through a caucus. Say what you want about WA, but it appears Bernie's actual support there vs Clinton was far less than the landslide he got in the caucus, assuming you maximized the number of participants.
You're right, the primary itself was meaningless as it was the caucus that officially counted, but you can't just ignore the results of the primary, which had almost 600,000 more participants. Quite frankly, it would be a real shame if we continued using caucuses to choose our candidates in the future.