If this guy has you in his crosshairs, which is probably several minutes before he actually shoots someone, you think he would pick you because of the shirt? This seems as likely as being the one to get shot by the sniper.
I absolutely think he would pick someone wearing the shirt. From what the police have indicated, this guy has an ego. If you are standing next to someone not wearing the shirt, you really don't think you would be the one he would aim at?