Must the Rightly Guided Caliphs and the rest of the Companions be exonerated from killing, or should one assume the best of them?

The Companions fought in the way of Allah, and they killed the enemies of Allah and those who deserved to be killed by right. They are not infallible from sins, such as killing unjustly, but it is presumed that such acts did not occur unless based on an interpretation.

Any fighting that occurred among them was based on ijtihad (definition) (independent reasoning), and they were either correct or mistaken. If a sin was committed by them, then their virtues and merits overshadow their flaws, especially the Rightly Guided Caliphs, for they are among the people of Paradise.

Among the principles of Ahl al-Sunnah (definition) wal-Jama'ah is the soundness of their hearts and tongues towards the Companions. They believe in their virtues and refrain from discussing their disputes, believing that whatever is narrated regarding their shortcomings is either a lie, or exaggerated and diminished, or they are excused for it due to ijtihad.

The Companions are not infallible from sins, but their sins are forgiven due to their precedence, virtues, and good deeds that erase evil deeds. They are the best of generations, and their righteous deeds carry a greater reward than those who came after them. If one of them sinned, he either repented, or his good deeds effaced his sins, or he was forgiven due to his precedence, or through the Prophet's intercession, or he was afflicted with something that expiated his sin.

The extent of their actions that are denounced is minor and overshadowed by their immense virtues and excellent qualities. They are the best of creation after the Prophets, and there is none like them.