Every Power 5 school in the country has stories like this. Hometown kids flies under the radar, doesn't get offered by his childhood school, goes to another school, has a good season or a good career, and people say "why didn't you recruit that kid?" Every. Major. Program. It happens all the time.
Was the kid destined to be a star but went overlooked? Was the kid motivated by being dissed by his dream school, and work extra hard to be something more to show people they were wrong? Was it something the kid didn't have when they were recruited, but the coaching staff at their destination school was able to tap into it? Was the kid a better fit for this school or that school's offensive scheme?
You never know with this stuff. It's not a science. And every Power 5 school has these sorts of "if only they'd tried harder to recruit them" stories.