That's amazing. I've been watching football for 50+ years and never knew that.
I don't think it was that way until this year. They tweaked a few rules trying to cut down on injuries this year and I'm 90% sure that's one of the ones they tweaked. And it kind of bites because basically it just hoses offensive players after a turnover. Dive low and hope the guy falls down is how offensive players do most of their tackles, because they don't actually know how to tackle and that's the safest surest way for a non-tackler to get somebody down (also defenders don't actually know how to leap over guys down low and avoid a tackle so it's more effective against them). But Randal El got nailed in both the Colts regular season game and the Bengals second regular season game for basically the same thing. Stinky rule but at least they applied it evenly.