I think it's possible that after the driver of the silver Audi picked EN up from the park (before TM & KM had left the parking lot of the school), they followed TM & daughter for a ways on the street. It could be that at that time the driver got out of the Audi and made his verbal threats to TM & daughter, believing EN's possibly paranoid claims that they "were after him". It could be that, afterward, the driver believed that was the end of it because maybe EN was frequently claiming that 'someone was after' him and the driver had been humoring EN by threatening TM.
After TM and daughter went home, dropped daughter off, picked up armed BM, they went out & easily located the silver Audi - perhaps because EN & the driver hadn't left the area, but were sitting in the car laughing about scaring the $h!t out of the occupants of the green car.
When TM & BM found the silver car nearby, BM may have brandished his gun to scare them (not knowing EN was armed & ready & willing to shoot). TM & BM fled the scene after being shot at, hoping the silver Audi wouldn't follow them home, TM likely realizing they'd made a huge mistake by going to try to confront them.
The silver Audi followed them home, with EN opening fire as they approached the Meyers' residence - shooting at the person he thought was heading toward the house and at the person near the car.
Feel free to poke holes in my scenario.
So your theory is that TM
did in fact go home, tell her son to get his gun, and took him with her to go out hunting for EN?
Do you have any theory as to why the original story was that Brandon was at home asleep and came out of the house to return fire?
Or any theory about why the part about Tammy going all vigilante and telling Brandon to get his gun and go out with her to hunt down EN was kept secret until 5 days after the shooting?
Or any theory about why EN described the incident to his friends that very night as one long incident in which he encountered the Meyers car, followed it home, and opened fire?
Or any theory about why TM, described as a warm, loving woman who mothered everybody, would want to take her son and his gun(!) out to hunt down a road rager after she had escaped and made it home safely?
These are serious questions. That version of the story just makes no sense to me. I can't get my head around the notion that a mother would escape a road rager, make it home safely with her daughter, and then, instead of calling 911, she would tell her son to get his gun and help her go out and hunt down the road rager.
Edited to add: Now, if the story was that
Bob and Brandon had armed themselves to go hunt down EN, I could probably buy that.