Six Forgotten Warriors Chapter 5: The Price of Heroism - S5-E6
Other mistake: Two scenes in this episode are shown out of order. First we see Captain America and Spider-Man lying on the ground near the dimensional vortex at the mercy of Chameleon and the Red Skull, with Cap flicking a rock across the room to distract Chameleon so that he and Spider-Man can re-engage them in battle. Shortly after, we see Spidey and Cap arriving at the dimensional vortex to configure it to defeat Electro, with Chameleon and Red Skull attacking them once Spidey has finished with the vortex, revealing they had been lying in wait knowing full well someone would figure out that the vortex was the key to stopping Electro.
Six Forgotten Warriors Chapter 5: The Price of Heroism - S5-E6
Other mistake: When Spider-Man and Silver Sable are chasing the Red Skull and Kragov, they are able to deduce which direction they are going by identifying their footprints. However, Spidey and Silver Sable themselves don't leave footprints when walking over the same spot.