Like you, until this story hit the news I had never heard of the guy.
The articles I've read say the two individuals were seen leaving the area 20 minutes (or so) before the [alleged] attack. They also say there's a one-minute gap in the video, so the actual attack isn't shown (how convenient), but within the span of one minute Smollett goes from condition white to having been insulted, beat up, and had a noose put around his neck. (And either fought back, or didn't -- depending on which version of his story you pay attention to.)
So far, IMHO, it doesn't add up. I think he created the entire story.