Stupidity: To save the people from rubble falling on their heads Flash does not move them aside like he did with his future love, but does some strange manoeuvre which takes seconds - since we see people moving normally - and happens in midair (how does he get there?) and that does not take care of a huge chunk of concrete which he does nothing about, shouting just "No!", but Cyborg has all the time he needs to load his Mega Man arm and vaporize it in midair. (02:00:00)
Stupidity: Wonder Woman is fast and strong enough to utterly murder (you can see blood prints on the wall for each person she knocks away) a dozen of terrorists shooting at her, but then with the fight already won she decides to finish off the last guy. So she summons in the room full of hostages an energy blast powerful enough to hurt a New God and that destroys the front of the building, creating debris that nearly kills the police force outside for massive damage to the municipality. What a hero. (00:24:10)
Stupidity: A massive fire of unexplained origin and uncommon persistence kept for hours the fire brigade busy at the Amazon temple, making news all across the world. Of course Diana just waltzes by without any security, media, scientist, and the mysterious arrow which started the fire was clearly not taken in as evidence or anything.
Stupidity: Wonder Woman gets back to confront the single terrorist still standing; he shoots a single bullet which she parries. The guy is stunned realizing what happened, switches to full auto, starts shooting in an arc. WW is quick enough to run and parry effortlessly and with precision every single bullet from an HK416 (over 700r/s), but somehow is too slow to jump him. With such godly speed, it's unfathomable she even gave him the time to react and switch mode. And she nearly gives him time to reload and fire later. (00:23:15)