I'd be leaning toward "yes", although I suppose the person could just be unintelligent (in reference to the inventory) and powereleveled/ran through Aza by others. Unlikely, especially since said powerlevelers would have probably known about better items, but still possible. @Shaper: Hell Memories, I think.
Conclusion: This is very probably a cheater, but there is no real way to prove it sans a confession or an inconsistency in the story of how hw got those levels/items.