I was pulled over by an officer and a few weeks later he called my Job and said I was tailgating him?

I asked if he was sure it was me and he said yes and that he saw my fAce so he ran my tag and then he said he had spoken to my supervisor about my driving. My question is this 1. Is he allowed to call my place of employment like that? - how embarrassing 2. I found out he was also speaking to a fellow co-worker about it that he is friends with- is he allowed to do that? He said he was giving me a 2nd warning as this is the reason he pulled me over few weeks prior. I'm not a good judge of space but I always have a good amount of space between me and other cars. I was pulled over because it wasn't 4 seconds worth. I'm paying attention to my normal driving and the closest I got to another car was 2 seconds worth I'm not even speeding. I dunno a little light on the situation would help thanks.