In that case, as I understand it, the voice actor intentionally mimicked Waits, purposefully using his intonations, style of speech, and phrasing, all of which were not natural to the voice actor. He was intentionally mimicking Waits. I doubt the same claim can be made of the Sky voice actor.
>>kaiwen+(OP)
Doesn't matter if the voice was natural or not if there are emails at OAI saying "find us someone who sounds just like ScarJo." I suspect there are and that's why SamA turned pussy and ran.