When Brock kicks the door in, Mr. White and Dr. Venture can be seen in the back of the room behind the original Team Venture. This should've been Hank and Dean, as Mr. White and Dr. Venture are still in the dungeon.
In the scene before the credits, Baron Ünderbheit is shown with his metal jaw back on his face, despite the fact that it was removed and taken by Brock earlier in the episode.
When Brock uses Ünderbheit's jaw to break his chains it shows him breaking the chain itself, then when he leaves the cell it shows his collar being broken open with the chain intact, then later it shows the chain being broken again.