First of all, we don't know if Harbhajan denied using the "Monkey" word in sydney. So long, no media or none claim such thing. (Ancipating that, I guess Mr Panickar already stated his wife example to justify Harbhajan either ways.)
My point is, it is not upto the player of international stature for 2 decades to decide. No body want to ask Sachin if Harbhajan is innocent or not. That is for the judges to decide.
What you want to hear is a statement from Sachin saying "I was there. Bhajji did not use the "Monkey" word."
Any other statement from Sachin like he is innocent would not help. If Sachin simply says he did not hear Harbhajan say such words, that would be construed as he didn't pay proper attention to the conversation. He is not a good witness in that case and he shouldn't have been there in that trial.