I’m 179cm, so right on the Specialized M/L boundary (32″-ish inside leg, normal-ish arms, slightly poor flexibility).
I have a L (19″) Crave, and it fits well. Feels good to ride (not at all barge-like) and riding small sizes feels a bit cramped.
The top-tube feels high when standing on the ground, but I’ve never had any problem bashing my bits during planned or unplanned dismounts.
Worth mentioning that the latest Specialized hardtails all have quite short stems, so comparisons with other makes frame geometry may not quite make sense.
I’d say XL, but he needs to sit on it to be sure!