Raising Doubts about Prophet sins

Narrated 'Aisha: Whenever Allah's Apostle ordered the Muslims to do something, he used to order them deeds which were easy for them to do, (according to their strength and endurance). They said, "O Allah's Apostle! We are not like you. Allah has forgiven your past and future sins." So Allah's Apostle became angry and it was apparent on his face. He said, "I am the most God fearing, and know Allah better than all of you do."

Sahih Bukhari Volume 1, Book 2, Number 19:

Here the people wanted to do more than that what the Holy Prophet ordered , and claimed that the sins of the Holy Prophet Muhammed Sallalaahu Alaihi wasallam are already forgiven but theirs are not , so they taught they need to do more, They were a few things which made the Prophet angry and though they did not become Khawarij like those who disrespected him directly, Still anger was displayed on his blessed  face1) The people did not recognize that Obeying the Holy Prophet Sallalaahu alaihi wasallam  is Obeying Allah

2) They tried to compete with him like he is an ordinary human being like them and did not recognize his exceptional status bestowed upon him3) The Holy Prophet Muhammed Sallalaahu Alaihi wasallam is the biggest intercessor for the forgiveness of sins

These reasons are apparent but they could be many more