Comcast has asserted from the beginning of the torrent-shaping fiasco that they only altered traffic when it was necessary. The FCC, after all its musings, has come to a different conclusion, it seems. Kevin Martin, Chairman of the FCC, has outright accused Comcast of lying, claiming that they shaped traffic even when there was no significant load on a particular node.
It seems the FCC's investigations discovered that the technology used to shape traffic was deployed over large regions, and may not even be capable of identifying when traffic demand was low or high. If that's truly the case, Comcast's claim to only stop torrent traffic when needed is a total falsehood. That said, with Comcast's new outlook on torrents and their supposedly friendly future dealings, things might change.