Something something Cam Fowler.
I think Fowler's case was just more a perfect storm rather than him being a DND, similar to Zach Parise dropping unexpectedly in 2003. Sometimes the way the draft is ordered, a consensus top 10 guy can fall out of the top 10 just because the teams just happened to have one more guy ranked higher still available. Anaheim would have happily drafted Fowler earlier if they had a higher pick.
At least for me, it also didn't seem coincidental that many of the teams who passed on Fowler in 2010 happened to use a 2009 1st rounder on a LHD. Obviously it seems silly that you would pass on Fowler because you just drafted somebody you were hoping could be as good as Fowler, but....
4. Columbus - 2009 1st rounder used on John Moore.
5. NY Islanders - 2009 1st rounder used on Calvin de Haan. They also seemed to make it known that they were looking for a long term winger for Tavares in 2010.
6. Tampa Bay - 2009 1st rounder used on Victor Hedman.
7. Carolina - Then GM Jim Rutherford had previously mentioned his distaste for drafting D in the first round because they take longer to develop (albeit ironic that they'd take Ryan Murphy the next year).
9. Minnesota - 2009 1st rounder used on Nick Leddy.
10. NY Rangers - 2008 1st rounder used on Michael Del Zotto.
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Ducati Boy's post also reminded me of a recent prospect Brayden Burke. He put up great numbers in the WHL and seemed worthy of at least a mid-late round pick. Apparently it was known that he had some off the ice issues, so he went undrafted three times. He was traded away from his junior club after being called a distraction. Vaguely recall that he got cleaned up and eventually signed with Arizona as a free agent.