Not every grab of the shoulder pads is a horse collar. Here is the whole rule below. Also notice it is "inside back" without a comma.

Grabbing the inside collar is not a horse collar. As I have understood it.


Horse-Collar Tackle
ARTICLE 15. All players are prohibited from grabbing the inside back or side
collar of the shoulder pads or jersey, or the nameplate area, and abruptly pulling
the ball carrier down. This rule applies to a ball carrier, including a potential
passer, who is inside the tackle box.




Sidenote (Soapbox really, probably best to ignore this): Looking at a lot of the comments (and likely my own comments history) I get the idea that referees probably roll their eyes at fans pretending to be experts the same way lawyers roll their eyes when they see defendants act as their own attorney.

Because when I see comments about refereeing the game, there is a vocal minority that are not arguing the calls, but really just showing they have not actually read the rulebook. (Which I admit, I assumed every has read the rulebook atleast once in their life, kind of like reading the Book of Mormon atleast once as a member . . . I have realized that is very far from the truth.)