I have no idea what happened.
However, to answer your question, if I had to come up with a theory, I'd say he and his entourage were at a club being swaggy and cock-of-the-walk. Some other dudes decided they wanted to mess with the hot-shot athelete. A fight breaks out and in the melee, two of these other dudes are stabbed dead.
I don't think Ray Lewis ever had a knife in his hand. However, he is a professional athlete and realizes "Oh fuck, this is a bad scene, I better split." When questioned by police, he fudges because these are friends of his that weren't necessarily "protecting" him but acting in his interests. Or maybe he genuinely doesn't know who did what. I can't imagine Ray Lewis was intently focusing on the details of the fight. But wanting to protect your buddies shortly after a traumatic event like this isn't out of the realm of possibility and doesn't mean you're a CAPS LOCK MURDERER. It means you made a mistake, and as Ray Lewis was convicted of a misdemeanor, the jury agreed.
And sorry, you can't just say it doesn't matter that the jury acquitted the two guys in Ray Lewis' group. It does matter. The jury heard the facts and said 'Not Guilty'. I think that's a slightly more credible argument than "Well I just pulled these emotions out of my ass and he is GUILTY GUILTY GUILTY"