Was Ven Maha Boowa an arahant and why?

and i’m wondering how big a part intellect plays in invariance of one’s spiritual accomplishment, would an arahant for instance still be an arahant having become mentally deranged or incapable? if one’s arahantship didn’t find expression in their conduct and way of thinking due to mental disability what would then constitute their arahantship, where would it be sitting? or would it still shine through despite all and any mental problems?

concurrently i’m leaning towards a view that spiritual attainment is unlikely for one whos mental problems prevent their intellectual grasp of the dhammic concepts or any relevant concepts for that matter