I destroyed Crafty in 20 moves!

[Côme Alexandre]

I played a game of 15mn+3s with Crafty 16.16 on my AMD k6II 350 today,and I destroyed it in 23 moves!!
Here is the game:
[Event "?"]
[Site "?"]
[Date "1/8/99"]
[Round "-"]
[White "Côme Alexandre"]
[Black "Crafty 16.16"]
[Result "1-0"]
1. e4 e5 2. Nf3 Nc6 3. Bc4 Nf6 4. d4 exd4 5. O-O Bc5 6. e5 d5 7. exf6 dxc4 8. Re1+ Be6 9. Ng5 Qd5 10. Nc3 Qf5 11. Nce4 Bb6? 12. Ng3 Qg6 13. Nxe6 fxe6 14. Rxe6+ Kd7 15. Nh5 gxf6?? 16. Rxf6 Qe4 17. Ng3 Qe8 18. Qg4+ Kd8 19.Rxc6 Qxc6 20. Bg5+ Ke8 21. Re1+ Kf8 22. Qf4+ Kg8 23. Nf5
1-0
I think 11...Bb6? is a blunder,the theoretical move 11...0-0-0 is better,but I don't think 11... Bb6? is the decisive error.
15...gxf6?? is the lost move,15...Rhe8 is better, the following should be: 16.Rxe8 Rxe8 17.Nxg7
Rf8 unclear position.
Could somebody explain to me :
How Crafty can play so horrible move like 15...gxf6?? ?
PS:Where can I find Lgoliath2000?
Best Regards
Côme Alexandre.