Tensions obviously run high in rivalry week, and refs are often cautious at calling penalties during scuffles between two highly emotional teams.
This one, though, appears to be a miss on the officials.
After Florida State blocked a Florida extra-point attempt in the first half, Florida State's Ro'Derrick Hoskins gets in a scuffle with a Florida player as the ball idly bounces away. After Hoskins takes a hit from the Florida player, he retaliates with what appears to be a firms open-handed slap right to the Florida player's helmet.
As you can tell from the video, the slap clearly made loud contact.
Usually any act of swinging at an opponents head like that draws a penalty, but it looks like either the refs completely missed it or simply ignored it due to the Florida player making first contact.
