I've always considered Blatt (and to a lesser extent D'Antoni) practically European...
Europeanised, influenced by the Euro hoops, but not truly European.
Mike D'Antoni - Virginia
Blatt - Massachusetts
I define European coach as the one that was born in Europe and learned the trade there.
Similar how many here (on the other side of the pond) don't even consider a guy like Detlef Schrempf as a true Euro, since he went to college there.
Dražen Petrović, Šarūnas Marčiulionis, Nowitzki those are "true" Euros.