UPDATE: SI.com's Stewart Mandel did some actual reporting on this story and here's what he found out from SEC spokesman Charles Bloom, who spoke to SEC coordinator of officials Rodgers Redding about the incident:
"The umpire's most vulnerable position on the field is right behind the line of scrimmage and sometimes gets right into the play. In this case, the umpire is there, he tries to defend himself by putting his arms up. The quarterback shifts direction a little bit and he puts his arms up.
"He makes an attempt to defend himself. I know it may look different on video, but what we see is that he makes an effort to protect himself."