Pidge no longer wears the helmet that he entered the cave with when he was last seen in the end of "A Ghost and Four Keys".
Sven is near the others when Pidge jumps at them, but cannot be seen a moment later as though he is nowhere nearby, then reappears standing just beside them.
Even though he is supposed to be wearing his spacesuit, during Pidge's journey through the caves and back to the castle, twice they cut to shots of him wearing his street clothes.
When the Voltron Force is dropping from the zip-line into the loading bay, it is Princess Allura that drops down with the guys instead of Sven. However, when the pods blast off, they once again show Sven with the team.