I wonder if we will ever find out who the person above them who bungled this is. Probably a civilian pentagon lackey; "Welcome-us-as-liberators-with-flowers" type of geek.
I'm always suspicious of "former delta force" types. But on the other hand I do feel like the US would nix the order to take out Bin Laden simply because it would make a martyr out of him. It's one of those tricky WWII Hitler scenarios. If you kill Bin Laden do his generals destroy the organization he created in an Alexandrian grab for power or do they use his death as a rallying cry to show the rightness of their way and the evil of ours?
I wouldn't want to be the commander who had to make that call.
If there's anything I've learned from reading accounts of Britain's ill-fated 1st Afghan war of (1839-42), and the Soviet intervention to support the Karmal government in Kabul (1979-89), its that loyalty to one's word is not an Afghan cultural value. We can support Afghans pursuing their own interests, but we should never depend upon their assistance in achieving our own.
Insofar as evading colonization for long, and maintaining their own insular culture, Afghan values work well. They're just irreconcilable with Western norms.