All perfect praise be to Allaah, the Lord of the worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad, sallallaahu ‘alayhi wa sallam, is His Slave and Messenger.
The majority of scholars state that the prophets, may Allaah exalt their mention, are only infallible with respect to committing major sins. However, some scholars say that they are infallible with regard to committing both minor and major sins. Al-Qaadhi ‘Iyaadh is among those who hold this opinion.
In sum, most of the scholars believe that prophets, may Allaah exalt their mention, were not infallible with regard to committing minor sins.
A person who believes that the prophets are infallible against permitting minor sins is not sinful - Allaah willing - because there are some scholars who hold that opinion, and because scholars differ on the issue.
Allaah Knows best.