Open Question: A question of loyalty and ethics in martial arts.?

A dear friend and training partner approached me about seven weeks ago and asked me to help him prepare for his first MMA fight. I gladly accepted.
We trained very very hard. I knew we had a strong chance at winning this fight. The days of weight ins everything changed. I saw the opponent. He was big, strong, and much more athletic than my fighter. I saw him shadowboxing when we walked in and knew that things had just changed.
During the fight the opponent came out very strong and fast. My fighter nearly ended the bout with a deep triangle choke but timed out. The next round my fighter lost by choke….
The question here is this, Did i betray my fighter by losing hope?
I stuck to the game plan we worked out, I encouraged him. But in my heart I did not feel good about the match. I feel very guilty and horrible about the whole thing… please, experienced fighters and martial artists help me out.