1) So I give the blinker first before changing lanes, like I always does.
2) So it happens fast, I was changing lane and suddenly I feel someone bumped into my car, while I was trying to control it as it spin, but again it happen fast and I won't lie I did not see the car in the side mirror.
3) There wasn't anyone, other side of the road there were people but view is blocked by mine road dividers.
4) No one stopped, As soon as my car stopped i rush out to check on other driver cause I was worried for other person, and he asked me if i am ok, than suddenly I saw a cop stopping by, i told him to give me a min to get myself together.
Thanks for your reply.
Please do know that I am not offering any legal advice, and at this point, my wife (who is a lawyer) would yell at me if I don't say you should seek actual legal advice on the issue. So this is that, what I say here is solely my opinion, and by no mean I am in any authority position or you should have follow it.
Judging from what you say, unless there is some evidence point to him speeding up, then it is most likely your fault. Because according to Florida Statue 2021 Chapter 316.085 (You said you were in Florida, right?)
316.085 Limitations on overtaking, passing, changing lanes and changing course.—
(1) No vehicle shall be driven to the left side of the center of the roadway in overtaking and passing another vehicle proceeding in the same direction unless authorized by the provisions of this chapter and unless such left side is clearly visible and is free of oncoming traffic for a sufficient distance ahead to permit such overtaking and passing to be completely made without interfering with the operation of any vehicle approaching from the opposite direction of any vehicle overtaken. In every event the overtaking vehicle must return to an authorized lane of travel as soon as practicable and, in the event the passing movement involves the use of a lane authorized for vehicles approaching from the opposite direction, before coming within 200 feet of any approaching vehicle.
(2)
No vehicle shall be driven from a direct course in any lane on any highway until the driver has determined that the vehicle is not being approached or passed by any other vehicle in the lane or on the side to which the driver desires to move and that the move can be completely made with safety and without interfering with the safe operation of any vehicle approaching from the same direction.
(3) A violation of this section is a noncriminal traffic infraction, punishable as a moving violation as provided in chapter 318.
So basically if you change lane, and he hit you, unless there is some evidence that you can secure to show that he speed up or you were otherwise in a safe manner, you are mostly at fault.
So without witness, and I don't think there are any tire mark you can trace, chances are you are really at fault if you indeed change lane and he hit you from behind. So what happen now is, do you want to make it public.
As
@gambit said, he can take your $400 and then still claim your insurance as he has all the document and evidence (He have your DL number, Registration number and on scene photograph, are you sure those were deleted, did you see him delete it or he just tell you he will? On the other hand, it depends on how far you are willing to go, you can report an accident after the fact and get a case number that way, but if he claim you again, lacking of a written agreement, you probably cannot proof that you pay him money, you have mentioned you pay him with cash app, can that be traced or do you have any kind of record?
So right now, If I were you, I will go to the Police station, make a MTA report. and then go look for a lawyer and ask for legal advice, but judging from the fact that you have given to me, I would say the $400 is long gone, and right now, what you need is damage control.