NO SHOES

Sotah 40 a  דאין הכהנים רשאין לעלות בסנדליהן לדוכן The reason Kohanim must remove their shoes for Duchening is, 1) there might be a Kohen with torn shoe strap 2) who will be embarrassed (to Duchen with torn shoes)  3) he will fix the strap  4)he will miss  the Duchening (busy fixing) 5) and people will talk and say he is a בן גרושה. (Pasula Kohen) To prevent this unlikely sequent of events ( all 5 things has to happen) all Kohanim must go through the טירחא (bother) of removing their shoes every time they Duchen. We see from here, how severe, Chazal considered embarrassing another Yid.