Rabbeinu Bachaye explains that the Korban Olah is a Kapparah for bad thoughts. Bad thoughts are not embarrassing as we haven't carried out our plans. Everyone is guilty of having bad thoughts and our job is to suppress them. However the Chatas is for actual bad deeds.
In order not to shame the sinner, says Rabbeinu Bachaye, when he stands in the middle of the Bais HaMikdash in public, we stand him in the same place as the person who brings an Olah so no one will know if he is really guilty of crime or not.
If this is how careful the Torah is not to embarrass a sinner, we can understand how important it is not to embarrass someone who has done no wrong!