Bycotron: @ goodevans, I had very similar thoughts to Jesspatrick about 10.Bb5 played by white in this game. Your post made me curious to discover the truth of the position and white's 10th move, so I fired up Rybka to help me out.
Rybka supports the conclusion that the move is a very significant mistake by white, let me see if I can explain why.
First of all, it gives black the option of justifying his c7 knight simply by 10...Nxb5 = (Rybka) when white has not increased his development at all and will soon see the position truly is dead equal, eg. 11.Nxb5 a6 12.Nd6+ Bxd6 13.Rxd6 and I'm certainly not feeling nearly as confident with white as I was before his tenth move! How can he make progress against the stout black position with no weaknesses?
10...a6?! is a gamble by black. As indicated, 10...Nxb5 was the most obvious and probably best way to take advantage of white's slip. Now white can bail out with 11.Be2 when we must still nevertheless acknowledge 10.Bb5?! was a mistake because black now controls b5 which he can either use to expand his Queenside pawns to attack the white King, or place a piece on (eg Nb5) to control important squares in the white camp.
14.axb3 and look how black's position is improved! His Bb7 is free, white's Bb3 is gone, white's King's castle is compromised, and black owns most of the space on the Queenside around white's King!
You indicated that black's next three moves lead "nowhere near equality," thus justifying the entire 10.Bb5 plan, but this cannot be the case.
Look at the position after white's 14th move and black has done more than equalize, he is obviously better and Rybka confirms the advantage has switched hands (from .7 before white's 10th, to .3 before black's 14th). In material terms, white's questionable judgement has thrown away a whole pawn's worth of the advantage.
10.Bb5 was a very significant error by white, but black returned the favor when he played 14...Nd5?! instead of the most obvious move on the entire board 14...b4 when black remains very slightly on top after eg 15.Ne4 Nd5.
Black let white back into the game, white continued to play accurately, and when black slipped again with 20...Qe8 white cleaned up beautifully! White played a beautiful game here, but it was not perfect, and that's perfectly okay. :)