The phrase "juristic reason" refers to the legal or official rationale or justification behind a decision, law, or rule. It explains why something is considered legal or acceptable from a legal perspective. Full definition
The established categories of juristic reasons include: contract, a disposition by law, donative intent, and other valid common law, equitable or statutory obligations. (fairinheritance.com)
Also, in the event overtime pay is found owing, CN Rail would clearly have been unjustly enriched since there was no apparent juristic reason why CN Rail should be permitted to retain the benefit of any unpaid hours of work. (mathewsdinsdale.com)
One of the established categories of juristic reason is contractual (Kerr at para. 41). (disinherited.com)