Can you get a speeding ticket from a person writing down your tag and giving it to the police?

alright. so here is the story. i was picking my friend up from her house and she wasnt home yet. so i drove around the neighborhood a few times. apparently i was "racing" so some nice sweet kind man... NOT! took down my tag. and then proceeded to follow me and so i got scared because i had been chased half way across town by some kids who live in that neighborhood. so i sped up and then i turned into a cul-de-sac (sp?) by mistake. and he began YELLING at me. trying to give me a lecture on how i was "racing" then i told him the story about how i had been chased and he said fine we can go down the street and talk to the sheriff and i said no thanks and he said well then dont be surprised if you hear about this later. basically, can i get a speeding ticket based off of his word? or what? pleaseee let me know ASAP thanks :))