Had this happen earlier this year, and wanted to get thoughts/interpretation.
Ball carrier is running along the sideline, and B clearly latches onto the inside back collar of the pads, and essentially 'rides' the runner 2-3 yards, then yanks him down, buckling his knees. I toss my flag for horsecollar tackle, (I'm a wing, and it's right in front of me) and B come us up to discuss. He saw the same thing, but according to his interpretation of the rule, since it was not 'immediate' in that he didn't pull him down immediately, he feels it doesn't meet the definition of HCT, and ultimately was waved off.
Actual verbiage of the rule is:
ARTICLE 15. All players are prohibited from grabbing the inside back collar of the shoulder pads or jersey, the nameplate area, or the inside collar of the side of the shoulder pads or jersey, and immediately pulling the ball carrier down.
This really seems like splitting hairs, but my understanding of the rule is such that the 'immediate' aspect is concerning the time it takes to actually pull the runner down, not a measure of time from when he hooks into the runner's pads.
Based on the exact wording, I think an argument could be made for either position.
Based on what I believe to be the intent of the rule (safety), it's a foul, whether the tackler pulls him down immediately after grabbing on inside the pads, or latches inside pads, (or any other place outlined in 9-1-15), rides/gets pulled for a while, then yanks him down, in accordance with the definition of a HCT.
Which interpretation is correct?
I wouldn't mind seeing a rules change to replace immediately with suddenly, or abruptly, to minimize confusion/errors in understanding on this.