Isn't HTV just a post production house and not an FX house? Give them a bit of credit. The live action stuff looks great. At the end of the day, CBS is responsible for quality control and this is the second time in a row that mistakes haven't been corrected before the discs go to press. Sure HTV's work is sloppy, but more importantly, CBS didn't notice or didn't care that the end result was subpar.
Well in CBS's defense, the second season DID have a bunch of original effects guys on board, plus the Okudas overseeing everything. I'm sure they assumed the work would be good.