Sergash: Shannon Clements is an untitled Irish player born in 1970 (he was 30 or 31 years old when he played that game).
I checked the game with the program Komodo 9.42 64 bits.
<3...cxd4> earlier that same year, Carlsen had played 3...Nf6 here, transposing back in regular lines later (see Richard Flores vs Carlsen, 2001)
<5...a6> In the mentioned game (Richard Flores vs Carlsen, 2001), Carlsen had played 5...g6 here, which had resulted in a victory.
<7.Bxf6?! Qxf6!> As SteveToyne wrote above, the most popular move here is 7.f4. I prefer Tennyson's comment, though: <Tennyson: 7.Bxf6 is played to simplify the position, but black gets full equality immediately.>
<9.Nf3N> This was apparently new at the time this game was played. 9.Nxc6 bxc6 10.0-0 Be7 = Egbert Clevers vs. Martin Vinck, Limburg Open Under 18 (Netherland) 2000, round 4, 0-1.
<12.Nd1> Not really a mistake, but 12.Rad1 was to be preferred.
<14.Nxe5?!> Dubious. 14.Qe3
<17...Qxd5> Forcing the trade of the queens. More precise was 17...Bc5+ 18.Kh1 Qxd5 19.Qxd5 Bxd5!
<19.Bf3?!> Not a good idea. 19.Nf2!