Dear Rabbi Kornfeld,
(a) I saw an explanation of Rabbi Shimon Ben Elazar's behavior in criticizing the ugly man, that he thought he was ugly because of misdeeds. Doesn't that contradict what we learned earlier that the more ugly a person is, the more Torah he is able to learn?
(b) Also, Rav Ada bar Ahava was upset that Rav Huna used him to keep the house standing until he could empty it because it would detract from his zchusim. The Gemara says that a person should not depend on a nes because of this. But Rav Ada bar Ahava was not guilty of depending on a nes, why should he have lost zechusim if the nes happened through no fault of his?
Gershon
(a) There is a type of ugliness which only the Chachamim are able to recognize (it is similar to Chachmas ha'Partzuf). According to the explanation which says that Rebbi Elazar ben Shimon thought the man was ugly because of misdeeds, that is the type of ugliness which the Gemara is referring to, and not to one who is physically unattractive.
(b) Even a person who does not rely on a Nes (that is, intentionally), nevertheless has a decrease in his Zechuyos when someone else is saved as a result of his Zechuyos. Whether he knew that he was saving someone in a place of danger or whether he did not know until later, the other person was still saved through this one's Zechuyos.
M. Kornfeld