816
I'm bracing myself for downvotes / banning, but I'm posting (from Minneapolis) to provide some context.
A more extensive, contemporaneous description of the convention is here, and the NY Times article geneva_conveniencel later linked explains a bit more.
My understanding / the short version is that the convention was very disorganized / poorly run, and didn't follow its own rules. Frey's campaign / delegates noticed irregularities right away, raised concerns (now found to be justified) that were dismissed, and ended up walking out in protest. It was understood that Frey wasn't likely to actually win the nomination, but could have feasibly prevented any endorsement (which Minneapolis DFL hasn't given since 2009).
My take is that Minneapolis DFL, whether from incompetence, or improper bias in favor of Fateh, or a conspiracy of Frey supporters in leadership that just wanted to provide grounds to invalidate the results, really fucked up here. Maybe Fateh could have still won the endorsement if all the ballots in the first round were counted, but we'll never know, because the second round would have been different. As it stands, I presume this is costing Fateh's campaign a bunch of money to reprint campaign signs/materials, pull ads, etc, that cited the endorsement.
I don't doubt that the establishment democrats would have found other things to complain about if Fateh had properly won this endorsement, but this was definitely not clean/proper, so withdrawing the endorsement is an appropriate course of action.