Stupidity: Medusa is the queen of the secret kingdom on the moon. She knows that they are very secretive and keep hidden from the humans on Earth who would have no idea who she is or that there are secret people on the moon. And yet in Hawaii, she walks up to an ATM and tries to demand by voice commands it give her money, saying, "I am Medusa of Attilan, and I need money." It is extremely stupid of her to think a random ATM in Hawaii would know who the secret queen of a secret moon base is.
Behold... The Inhumans - S1-E1
Character mistake: When Hunter One and his men are trying to sneak up on Gorgon in the jungle from behind them, Gorgon chuckles and says, "Never approach downwind, dumbass." He then proceeds to counterattack them. This implies he smelled them coming with the wind. However, this is backwards, as they would need to approach from upwind for their scent to carry to Gorgon. Approaching from downwind would be correct. So he should have said, "Never approach from upwind, dumbass." (00:33:35)