When Sora and Edo duel Zarc, Edo uses Destiny HERO Dystopia Guy's effect to destroy 1 of Yuya's Supreme King Servent Dragon Darkwurms. This allows Sora to attack and destroy the other Darkwurm with Des Toy Mad Chimera and have a flashback to the first time Yuya and Sora dueled. On Zarc's next turn he pendulum summons back the two Darkwurms and Edo activates D Hyper Nova to destroy the special summoned monsters followed up by Sora activating Des Toy Mad Parade to nuke Zarc's field. However its all for naught because of the [anime] effect of Astrograph Sorcerer bringing the cards back to the way they were. Then Zarc proceeds to use Astrograph sorcerer to summon Supreme King Z-Arc and OTK them.
Now, what would have happened if Edo had targeted either of Zarc's scales with Dystopia Guy's effect, It can target pendulum cards in the Pendulum zone since it did it that in EP 104. Zarc would have used Astrograph Sorcerer to bring the scale back, but Sora would be able to get rid of Astrograph Sorcerer before Zarc's turn when he could use its other effect and OTK them. Also, regardless of weather or not Sora could overpower Astrograph Sorcerer, the two trap cards mentioned above, D Hyper Nova and Des Toy Mad Parade would nuke Zarc's field when he attempted to special summon anything. I don't feel there is any justification for Edo's choice of target because though being able to attack the other Darkwurm would result in more damage, or so they thought before learning about Supreme King Gate 0 and Supreme King Gate Infinity's [anime] effects. The correct tactical choice at the time would be to target a scale and prevent Yuya from pendulum summoning next turn unless he had another compatible pendulum monster in hand. Its well known to them that pendulum monsters can be re-summoned at this point in the series. Also, there was no way that Edo could have known about Yuya and Sora's first duel before Sora mentioned it later in his turn so misplaying to appeal to Zarc doesn't make sense either.
I don't feel that this is comparable to Harald attacking Yusei on the turn that Gjalager (sp?) Horn would activate or IV not attacking Nash's Number C101 with Disaster Leo when he had the chance. Though those scenarios would have changed the outcome of those duels. In both cases the trap card that was set by the victor was something they'd never had in an on record duel before but it could have been Reflect Barrier in Yusei's case or Zeus's Breath [English name: Poseidon Wave] in Nash's case which had both been used by their respective duelists before and would have made Harald not attacking or IV attacking a fatal mistake. Yusei's "poker face" also helped in his case.
I don't think that Edo's misplay is as bad as the team Unicorn Duel though.