Ibn Abbas (may Allah be pleased with them both) said that the Prophet (peace and blessings be upon him) paid the diyah (blood money) of two free Muslims for two dhimmi polytheists, because they had a covenant with him.
Al-Hasan bin Umarah is matruk (abandoned) and is not used as evidence.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الديات / 16351