When was a block on the side

Ever called a block in the back?

NFL Current Rules

I've looked at it a bunch. I watched that game as a kid.

I'll have to dust off the rule book from when I was a HS kid and refereeing pee wee football as a side hustle

But this is the point

"The use of hands on the back is not a foul when:

a player is making a personal attempt to recover a loose ball

the opponent turns away from the blocker when contact is imminent

both of the blocker’s hands are on the opponent’s side. (If either hand is on the back, it is a foul.)"

Again, LT would have had to put his hand on Joe's back for it to be a block in the back.

Under the shoulder on the side isn't a block in the back. It isn't now, and wasn't in 84 either.