The events in this panel makes the entire story arc meaningless.
The heroes didn't resolve the action. That's a huge 'no no' in stories of any sort, whether literature or gaming. The PC's were made to stand by and watch the issue be resolved by NPCs. The PC's contribution has been negligible. Ultimately, the whole battle out there (that they lost) is meaningless, and was rendered even more meaningless.
This was not good DMing by any stretch. Most players I know would go into rebellion by this point because they got railroaded and they'd been gaming for a couple dozen sessions only have to have thier oppurtunity to be the hero snatched from them by my uber-NPCs (Soon, Miko, etc.). This wasn't even RBDMing. RBDMing would be Miko kills Soon, becomes an anti-paladin, Xykon gains direct control of the snarl via his rituals, allowing him to begin remaking the whole world in his Dark undead image, but now power mad goes to gain control of another (larger) gate in order to gain even more power leaving his new minion Miko in charge of protecting the sapphire (irony, no?), and the Order of the Stick is forced to fight thier way through Miko's undead forces in order to destroy the gem themselves, organize the citizens (many of whom are traitorously swearing loyalty to Miko) to kick the hobgoblins out of the city, and then after managing that go chasing Xykon (who already has a huge headstart) to the next gate before he can successfully gain over-God like powers.
The story did not get more complicated. The story was vastly simplified by this turn of events. Miko hit the reset button. Miko flipped the power switch. Back to page 1, with no character advancement on anyone's part (not even Miko's).
Compare this to the story arc when the last gate was destroyed. Still a draw, but its the PC's and not the NPC's who resolve the action. It's the PC's who shoulder the blame. Even, "Red fires true when the goat turns" showed alot more planning. It was a resolution. It was a climax. This isn't. This is a fizzle.