Was Mansur Al-Hallaj execution Islamically justified?

Mansur Al-Hallaj was a teacher of Sufism, and wrote a lot of poetry and was accused of heresy in accordance to Islamic law. **My main question is:** **Was Masur Al-Hallaj's execution Islamically justified?** My issues to the matter are: He was a writer of poetry, poetry is not literal but allegorical. According to my reading of Islamic history, Muhammad (swt) loved poetry. (His conviction of heresy was based on his poetry.) As well as far as my research goes, Mansur Al-Hallaj never admitted to heresy. **My second question:** **The Abbasid Caliph Al-Muqtadir who believe he was doing the proper thing to Mansur Al-Hallaj for heresy, what is his fate if Masur Al-Hallaj was actually innocent?** *Note: Just in case any thinks this question is mostly opinion based, it is not. I am clearly focused on whether Al-Hallaj's execution was Islamically justified based on Sharia law.*