I'm going to take a stab and broadly classify his style as a derivative of New York (ET2) style. I think he's (jokingly?) called it Aussie style before.
Oliver is a skilled enough dancer to dance whatever style he wants, and look competent/good at all of them.
However, it's my belief that professional dancers usually perform onstage according to their personal preference -- and I think that all of Oliver's Salsa performances that I remember seeing are On2 (ET2).
From what I have seen, he mostly dances ET2 style, and that style has influenced his dancing the most; meaning, even when dancing "on1" his styling and technique look (at least to me) like ET2 style.
In his school he teaches linear on1 (not LA, the "international" on1), and a bit of cuban. He used to teach on2 a couple months ago but now it's another guy who does the on2 lessons. Socially he dances mainly linear ET2, and sometimes on1 or even cuban if his follower asks for it.