BTW, the article itself is great. Offenses were dominating due to the rule changes that allowed offensive lineman to grab inside the numbers, much more use of the hands. Many defenders had never actually practiced ways to keep from being grabbed.
Inosanto was the first to teach NFL defensive players how to counter the grabs that were now legal for offensive linemen to make. One coach I saw in a documentary kept saying over and over to his defensive lineman the key was 'get your hands off first'. Don't wait to get grabbed, the Oline guy is often standing up straight or backing up on pass protect plays looking to grab you and move with you as you come at him. "Get your hands off first' meant getting your hands up before he does to be ready to CONTROL his hands as he tries to 'find' you.
Defensive players had to be trained to watch the offensive lineman's hands and learn to parry them, knock them aside and move past them. You go back and watch the line play in games from before the rules changes and you don't see the 'hand combat' at the line that is now so familiar to us.
Dan Inosanto helped play a role in the way line play is done in modern football. After he & others trained defensive players in 'hand combat' to avoid grabs, guess what happened? Team's hired martial artists to teach their offensive linemen how to COUNTER what the defensive linemen were now doing.
The game is constantly evolving.