Casting lies

Below the main cast for the characters in the show I keep seeing credits for other actors, John Dimaggio, Gary Anthony Williams, and so forth.

When I read that John Dimaggio voiced the burbot in the first episode... I knew something fishy is going on here.

There's inaccuracies, and even false-advertisements, but then there are lies! Someone is outright lying giving people the wrong impression!

If there is any proof thou that if the supporting cast is accurate, I'd very much like to see it.