It's definitely a horse collar tackle. The only question is: was Murray still in the pocket? If he was then this is not a penalty.
Here's the rule, as posted by The_Zone elsewhere in this thread:
No player shall grab the inside collar of the back or the side of the shoulder pads or jersey or grab the jersey at the name plate or above and pull the runner toward the ground. This does not apply to a runner who is in the tackle box or to a quarterback who is in the pocket.Photo from this article: [
theramswire.usatoday.com]
AlbaNY_Ram