Was the cause of 'Amr ibn al-'As's distress and uncertainty about his fate at the time of death his failure to side with 'Ali (may Allah be pleased with them both)?

The hadiths narrated in Imam Ahmad's Musnad clarify the reason for the distress of the great Companion Amr ibn al-Aas (may Allah be pleased with him) at the time of his death: it was his fear of meeting his Lord and being held accountable for his actions during his governorship and authority, and his uncertainty as to whether he had done good or not. It also mentions that his life passed through three stages: as a disbeliever, then as a Muslim who felt shy before the Prophet (peace be upon him), and then as one who assumed authority. He did not know if this was for him or against him. He enjoined that no one should weep over him or praise him, that he should be buried simply, and that people should remain by his grave for the time it takes to slaughter a camel, for comfort.