There are variations that are being reported.
Howlin has an opinion based on her local sources.
There have been four reports that I have heard about or have read.
1) DOT worker was investigating scene and came across the car. - The question is why was the DOT worker on the scene
2) A helicopter rented by the family found the car and called it in
3) A helicopter rented by the family found the car at the same time DOT did
4) The uncle and another relative found the car
It is mostly likely what Howlin states but the facts will come out in the next few days.
My source is the PILOT of the helicopter.
You are a real piece of work.
Your #1 is not correct and wasn't reported that way, of the articles I saw. The DOT worker just happened to be working close to what turned out to be the scene of the accident.
The DOT worker was making bridge repairs elsewhere and saw the luggage floating in the creek, then reported that. He/she was not there looking for the accident or doing any investigating.