http://revach.net/article.php?id=4722

Section: Parshas HaShavua   Category: Quick Vort
Parshas Ki Seitzei: Kli Yakar - Turning Your back On Your Friends Painful Loss
לֹא-תִרְאֶה אֶת-שׁוֹר אָחִיךָ אוֹ אֶת-שֵׂיוֹ, נִדָּחִים, וְהִתְעַלַּמְתָּ, מֵהֶם:  הָשֵׁב תְּשִׁיבֵם, לְאָחִיךָ, You may not observe your brother's ox or his sheep lost and conceal yourself from them, you must return them to your brother.  (Ki Seitzei 22:1).  The gemara (Brachos 19a)  says that we also learn from the wording in this pasuk that sometimes one may look away from their friends lost object, if the person who sees it is a Zakein and it is beneath his dignity to retrieve this item in the street.

The Kli Yakar says that we see from here a remez to the Mishna in Pirkei Avos (4:23) "Al Tishtadel Liroso B'Sha'as Kalkalaso; Do not try to see your friend is his moment of defeat."  The Mishna is teaching us that when a person suffers, it is entirely possible that we also deserve that fate.  Therefore, it is improper for us to watch and comment on the matter.  (Lot's wife was punished for this when he turned around to see Sidom being destroyed.)

לֹא-תִרְאֶה אֶת-שׁוֹר אָחִיךָ אוֹ אֶת-שֵׂיוֹ, נִדָּחִים, If your brother's money or child or anything else is a Nidach, lost without any hope.  וְהִתְעַלַּמְתָּ מֵהֶם, do not even look, but rather turn the other way.  You must make believe you don't see and don't know.  Observing and commenting is never useful, helpful, or permissible.  You will only embarrass him and you may be no more righteous than he.

However, if הָשֵׁב, there is a chance to save it.  Then תְּשִׁיבֵם לְאָחִיךָ, you must do everything in your power to get involved and return it to your friend.