Audio cuts out at 0:19 for a second, but continues seamlessly at 0:20. I'm not sure what can be done about this, as this is how the files are, both in the extended version and when viewed individually- That mute part is absolutely mute.

Check artist: Sakugabooru credits "Hiroaki Arai" as the animator of the bigger chunk of this animation, but it does not clarify who did the part from 0:00 - 0:05 nor the 0:19 - 0:20 moment. Thus, it is unconfirmed whether or not they also animated those portions.