The Stick's worst blunder: vote now!

[Porthos]

I think their worst blunder is objectively when they failed to destroy Xykon's phylactery, which would have possibly prevented the entire plotline from ever occurring, as Redcloak spends another 30 years trying to find a sorcerer to complete the ritual with.

Hard to call something a blunder if one doesn't know one is supposed to do it.

(Might count as Eugene's blunder for not telling Roy, however)