I tend to agree. Strictly speaking, he's not saying "Terrion Arnold is connected with two men who were arrested for armed robbery." Instead, he's saying "A FOX station in Florida is reporting that Terrion Arnold is connected..."
It's a fine line, and when you're Florio, with a large audience, there comes a responsibility to do more digging than just retweeting. Hell, I think I did a better job of posting the story here in my first word being "unverified."
This isn't that far removed from if Florio had reported fake news promulgated by a Twitter Bot. Can't do that. And it will cost Florio, to the extent TA's agents (Klutch Sports Group, who represents ~200 professional athletes including LeBron and Jalen Hurts) have now likely put him squarely in the dog house.
But as it stands, I can't really blame Florio too much for re-reporting what on its face appeared to be legitimate news.