He saw a guy in a suit with a crew cut - could be the secret service. See how the Secret Service dealt with a reporter in an earlier incident.
“Given the similarity in appearance between Lewandowski and the security official, and given the fact that Lewandowski was walking on the other side of Trump from where Fields was at the time, the possibility of mistaken identity cannot be ruled out. Indeed, given Lewandowski’s adamant denials (coupled with statements inappropriately impugning Fields’s character), it is the likeliest explanation.”
The above is from a Breitbart report! Even they know it’s BS. Link:
http://www.breitbart.com/big-government/2016/03/11/trump-presser-ben-terris-misidentified/