The backstory -- back in 1993, a 17-year-old Iverson was sentenced to 15 years in prison for allegedly hitting a white woman at a bowling alley during a brawl.
Brokaw heard about the situation -- and felt it was wrong for a teen with no prior criminal record to get such a harsh sentence ... so he featured the story on the national news.
It was a huge turning point -- and the conviction was eventually overturned. Iverson has publicly praised Brokaw for getting the ball rolling.
So, when we saw Tom out in Cleveland Monday morning -- we asked about the situation ... and Tom explained why he did what he did.