10 Police Showed Up For A “not Maintaining Your Lane”

My husband was driving with our 7 year old daughter to pick me up from work at 11:30pm (my car isn’t working right now), and was pulled over. As soon as he was pulled over he called me like he does every time bc he’s a black man in America. The cop instantly asked for his license and registration which then my husband asked the cop why was he getting pulled over and the cops response was “not maintaining your lane” my husband asked how and he said “you touched the white line one time back there”. He gave the cop his license and registration along with his licensed gun, cop walked back to his car, as soon as cop got his car another cop pulled and starting walking a K-9 around my husband’s car. The cop who pulled him over didn’t tell him he smelled anything or suspected anything and didn’t tell him that a K-9 was coming, and the cop with the K-9 didn’t announce he was walking around his car. He walked around his car 4 times and the fourth time was physically touching my husband’s car. They told him to get out the car bc the dog hinted on an air sniff, but yet never told my husband there was probable cause to even bring out a K-9. My husband said he was not going to step out the car and would like to speak to his supervisor. The cop kept asking for him to get out and my husband kept repeating he did not feel safe stepping out and would like to speak his supervisor. The cop asked my husband to turn his car and put the keys on the dashboard and he did. The cop reached inside his car and took his keys. My husband said “you’re not allowed to reach in here. That’s illegal.” The cop said he could if he wanted to. The cop said my husband was impeding the investigation, my husband asked him what was he being investigated for, cop said going off the dogs air sniff, he asked why did he have the other cop bring the dog since he never stated a probable cause and he said he didn’t have an answer to that, but that if he didn’t get out he would have the door ripped off his car and would take his daughter away from him. At this point I started recording the convo on my phone bc I was still waiting at work. My husband asked to speak to the supervisor multiple times and the cop kept talking to him asking questions like why he had air freshener in his car. My husband said I will not answer any questions unless it pertains to why I got pulled over not maintaining my lane which I still haven’t been citied for. At this point 8 cops are there. Another cop had then told my husband to Google Pennsylvania vs. Mimms case which my husband said he would not, but when I googled it says police can order a driver out of vehicle if the police feel their life is threatened. Not once did the cops say they felt worried or threatened. When the supervisor finally showed up (10 total cops now) he asked why he refused to get out and my husband said bc I know as soon as I step out I lose my rights and I’m scared for my daughter’s safety. At this point I’m on the way to them (co worker was taking me). It’s 25 degrees outside windows rolled down with my 7 year old in the back who is telling me that she is freezing and the cop is saying “I know it’s cold it’s almost over. They’re about to let your dad go”. And they let him go with a warning not maintaining his lane never stating a probable cause for everything and told him they “don’t write tickets out here”. Is this legal? We live in Nashville, TN but this happened in Sumner County TN. I do have all of this still on recording and the cops announced they had body cam going.