Not going to pretend like I’ve watched all the snaps, or even say if the article is right or wrong. But I can only assume they are actually watching the snaps and Horn had coverage snaps where the ball wasn’t thrown his way but his man was deemed open. Which seems plausible if opposing coaches just decided to avoid Horn in general whether his man was open or not. South Carolina was awful going 2-8 and giving up 451 yards of offense despite Horn giving up little to nothing all year. Clearly there were plenty of weak spots to exploit without having to deal with Horn and risking a turnover.
But again, this is just me making assumptions trying to make sense of the article.