The sefer "Chofetz Chaim" is accepted worldwide as the leading authority in the Hilchos Shemiras Haloshon arena. However, as with every area in halacha, there are specific details which are subject to debate among the poskim. (See this answer, for example)
Can anyone cite examples (with sources, if possible) of contemporary Poskim who disagree with some of the Chofetz Chaim's conclusions - either l'chumra or l'kula?