If your not someone who promotes racism and bigotry, then you really have to watch the manner in which you say things cause what you said was very abrasive and callous. (*note* mostly to people that have been on the recieving end of racism, and not the people who are on that bandwagon promoting it)
YOU specifically stated that as soon as you saw them, you KNEW that he wouldn't be convicted BASED on the black people in the jury.
That is as good as saying that they weren't going to weigh the evidence which was STACKED against OJ, and that regardless of what the prosecution presented, that they were going to vote for aquittal soley based on their ethnicity whether he was guilty or not.
To say that if OJ was tried in an all white jury that he would have gone down for the crime, is an attack on the black community and their ability to make impartial jury decisions. It promotes the thought that white guys better.
If you had stated that "in the news, they said that if he had been tried by a jury of white guys, that he would have been found guilty", it would have been a COMPLETELY different statement, but you didn't do that. You used your own thinking and your gut instinct as an example of what would have happened. As a result, your gut instinct displayed blatant racism and bigotry wether you meant it or not.
Which in turn reflects your belief system. If it didn't, then you need to learn how to communicate better.
Anyone who has experienced racism and bigotry can tell you that it was a racist comment. If you don't understand that what you said comes off the wrong way, then that error in how you convey information should be pointed out.
If your not a racist, then learn how to TALK like a non racist and learn to have some TACT!