The 'foul play' part was more of an "and also..." It talked about how the new mouthguard lights up "if the impact is severe enough to potentially cause a concu

The 'foul play' part was more of an "and also..." It talked about how the new mouthguard lights up "if the impact is severe enough to potentially cause a concussion". So, not just regular head impact it seems. Then mentions that it's an update to the current "smart mouthguard" which uses Bluetooth, because with "the current system the alerts can take several seconds to reach the match day doctor.". So, it's not just about flagging something illegal but actually goes to match day doctors when the impact is severe. This new one let's people/ref know to wave a doctor over quicker/send them off At the bottom they added that "the technology could also help identify instances of foul play."