Weren't the audio errors caused by outsourcing the authoring of the Blu-rays? I think I heard that the sampler was authored in-house, hence why EaF was correct on the sampler, and messed up on the season disc. I don't think CBS ever officially stated what the cause was (and what they would do to prevent it in the future).
If so, then CBS has definitely not learned their lesson trusting outside companies to take care of their products.
I believe it was actually the opposite in this case: CBS authored season 1, instead of outsourcing it to a company that specialized in the authoring like they did the sampler. I believe a member here and/or in the bluray.com forums worked for the company that authored the sampler and he pointed out some aspects that CBS should have done better in authoring (to improve quality and such) S1 that would have been done if an experienced company did it.