I can say, without hyperbole, that he squares up in a defensive position and then delivers a nice shoulder blow.
The umpire, Wilbur Hackett, Jr., knows how to deliver a forearm shiver, too. He was a Parade All-American from Louisville and a three-year starting linebacker at Kentucky from 1968-70. He was the first black captain in SEC history.
The SEC reviewed the play and believes Hackett was protecting himself and said no disciplinary action would be taken. Rogers Redding, the conference's coordinator of football officials, reviewed the tape of the play and thought it was inadvertent contact.
"Garcia changes his direction just a tad, which ties up the umpire just a tad and makes it look a lot worse than it really was," SEC spokesman Charles Bloom said.
"The umpire position amongst the officiating crew lends itself to more contact than any other official on the field. ... We feel there was nothing else that needs to be read into it and it was a collision between a player and an official."
So, the SEC thinks Hackett, Jr. was in the right position. I totally agree; if by “right position” you mean properly shuffling your feet, while remaining in a defensive posture and bringing down the ball carrier.
Alternative video here: