The subtitles are available here - http://www.amara.org/en/videos/2X4iBBif3jnx/en/1429060/

Everything below "production process will include following steps" makes it clear that original artist is not involved. See also this text - "The money collected from this campaign will go for production of one motion comic video, based on the «The Potion Contest» episode".

CC-BY license doesn't require approval from original author. But in this case there is an acclamation anyway - https://twitter.com/davidrevoy/status/768197367833038848

Here's a more in-depth nod of approval from the original artist:

http://www.peppercarrot.com/ar/article380/motion-comic-proje...

It's a mandatory requirement of license to "give appropriate credit" - https://creativecommons.org/licenses/by/4.0/deed If author of the campaign wouldn't put David's name on the artwork, then that would be violation of license condition. Let me know if you can specify any other way to "give appropriate credit", without mentioning the name of original author. ^__^