Other mistake: When Tommy is ambushed by the putties, he kicks one which explodes despite the fact that the Z on the puttie's chest never glowed white like they always have in previous episodes.
Audio problem: When Tommy is fighting the last putty before Goldar transports him, there is a contact noise made as he rolls over the putty's back; no hit was made on that manoeuvre.
Answer: Probably to save on costs of filming the same scene. In the reused shots they have always morphed so you can't see the actors. They just have to pay them to do voice-overs rather than the entire scene.
Ssiscool ★