The theme of this part of the footnote is that there is no excuse to speak lashon hara even if you are trying to save your name by blaming someone else even if it is true unless there is no other way to prove your innocence. But if you can prove you are not guilty without saying any names of who is wrong then it would be lashon hara to be name dropping.
There are a bunch of cases in the gemara that seems to be going against the halacha that you can’t speak out if you were personally involved. The first case brought was from gemara Brachos 5b Rav Huna complained to Rav Yehudah that his sharecropper snatched most of his wine. Rav Yehudah asked, why are you telling me this? It seems that Rav Huna wasn’t worried that anything more would be stolen, and he had no intention of the rabbis rebuking the sharecropper. The only thing was he wanted to clear his name because Rav Huna withheld part of what he was supposed to give to the sharecropper since the sharecropper stole his stuff. How was he able to do that?
We see from the gemara in Bava Basra 164b that Rebbe reprimanded his son Rebbe Shimon bar Rebbe when he brought him a get mikushar, special kind of divorce bill that was folded and sown together without a time by the date. Rebbe asked where is the time, his son responded maybe it’s inside the bill we should open it up. Rebbe opened it up and it wasn’t there. He looked at his son angrily and his son said I didn’t write it; Reb Yehuda Chaita wrote it. Rebbe responded, why are you speaking lashon hara? If that’s the case, why is Rav Huna any different, in both cases blaim is just being moved to someone else and the speaker is just proving, truthfully, his innocence.
However, there are two reason why Rav Huna was permitted to say what he said. First off Rashi alludes to the fact that this sharecropper was a known thief so it’s not lashon hara to blame him for what he did and second, Rebbe Shimon bar Rebbe did not have to tell his father who wrote, he could have just said I did not write it, but Rav Huna had no choice but to reveal what happened which obviously showed who was in the wrong.
In another episode in Gemara Erechin 16b, Chiya bar Rav complained to Shmuel in yeshiva that Rav Huna was bothering him. Rav Huna said he would stop. After Chiya bar Rav Rav Huna told Shmuel that he was doing something wrong to me. Shmuel asked why didn’t you let me know that beforehand? Rav Huna said I didn’t want the son of Rav to be embarrassed on my part. Rav Huna’a intent was to push off blame from himself without embarrassing Chiya bar Rav for the sake of the truth, but he had no choice for it to be known that Rav Chiya bar Rav had done something wrong.
However, to be allowed to prove your innocence at the expense of the revealing the guilty party when permissible one has to be very careful to meet the prerequisites that will be discussed in halacha 14, for if not, it is guaranteed he will stumble into speaking lashon hara. If you aren’t trying to take the blame off yourself but you aren’t trying to degrade anyone else, it is still lashon hara because someone is degraded whether it was your intention or not, even if it is true, as we saw in chapter 3 halacha 3.