In March 2011, Matt Cutts of Google told us Google does indeed have exception lists or what you call whitelists, but a week or so before that, he said they don't exist for search algorithms.
Google's John Mueller in yesterday's Google+ webmaster hangout addressed a question where he went into the whitelist talk. John basically said that for some algorithms Google does have a whitelist but for others, they do not.
He did specifically say that for the Penguin and Panda algorithms, a whitelist or exception list does not exist.
John said, and I am not quoting exactly, but close:
For the most part we do not have a whitelist where we can say this web site is okay and we can take it out of the algorithm. For some individual cases, we do do that. For a lot of the general search algorithms, we do not have that ability. But for others, we do have that ability, such as with the SafeSearch algorithm and false positives on adult content.They can add those sites to the whitelist manually for the time being until they fix the algorithm.
But Google does not have that for Panda or Penguin algorithms. So it depends on the algorithm.
This should not surprise most people, being that very prominent sites do get hit by these algorithms and Google's hands are tied until they refresh the algorithm.
Here is where the question starts, but it takes some time for John to get into the Whitelist part, that starts at 25 minutes in:
Forum discussion at Google+.
