However, my concern was and is with the decision by some witnesses to alter the pricefeed with a positive bias.

Ah yes I agree. However, not enough witnesses did that to make any appreciable difference.

Remember, the blockchain takes the MEDIAN of the witness values (middle values after sorting), so only two witnesses making the adjustment wouldn't do much if anything. The biased values all will end up at one end of the sorted list and not be used. (The purpose of using the median is to discard outlier or inaccurate values that are submitted for various reasons including, as in this case, non-consensus policy opinions, as well as malfunctions, delayed updates, etc.)