Dr. Awkward said:Actually, he said:
Emphasis mine.
Instead of being a fighter, he went with warlord. Why? Because he could gain synergy from the benefits of having a high Int in both warlord and wizard. I think he's a multiclass warlord/wizard.
Karhun began in the 3rd Edition era of Dave’s game as an illumian warblade/warmage. These days, he’s a 10th-level human warlord.
Emphasise mine

So yeah, he is multiclass, in some sort of hidden/mystic 4e way we do not yet know.. But he has no actual levels in wizard