Ulhumbrus: If we compare the opening of this game with the opening of the game
Fischer vs Geller, 1961 in the latter game Geller did not play 6..h5 but played instead 6...Bh5. Fischer then did not play 7 Bxc6+ at once but played first 7 c3 Qf6 8 g4 Bg6 9 d4 ( sacrificing a pawn to open the game)9...Bxe4 10 Nbd2 Bg6 and only now 11 Bxc6+
It may be that the exchange Bxc6+ becomes justified only if Black cannot find safety other than on the queenside.
8 d3 makes no attempt to open the game. Perhaps the idea is to threaten hxg4.
8...Bxf3 relinquishes the bishop pair. Instead of this 8...Bd7 keeps it.
After 9 Qxf3 Black's c pawns are doubled and his king side is more exposed than White's. The exchange 8...Bxf3 begins to look like a serious mistake.
Is 10 Qd1 necessary? 10 Qe2 keeps the back rank open. If Black castles on the queen side the queen will have lost only one tempo.
10...g5 looks like a completely unsound attack. However it is up to Anand to find a good answer to it.
Instead of 19 Nc3, 10 c3 supports the advance d4.
12 g3 disturbs the king side pawns without necessity. Anand wants to prepare f4.
16 f5 opens the h2-b8 diagonal. Instead of this 16 Be3 gets the bishop out.
Perhaps the right course for White was to try to complete his development and prepare the advance d4.
Anand may have overlooked something somewhere. It takes just one oversight for the game to go completely wrong.