If you feel that fault is not established it is not clear why you would have paid a cent on the first claim. Your post raises far more issues than can be addressed, and where there are so many issues, you need to actually retain an attorney to review all of the facts in detail, far beyond the capability of a summary posting.
The lowest you can offer? Zero. (0) It happens all the time.
This answer is offered for informational purposes only. It is not offered as, and does not constitute, legal advice. Laws vary widely from state to state. You should rely only on the advice given to you during a personal consultation by a local attorney who is thoroughly familiar with state laws and the area of practice in which your concern lies.
Generally you can file bankruptcy even though you "broke the law" by not having insurance, the cause of the accident was the negligence of a person not failure to have insurance. In your state there may be a limit of damages you are responsible for you need to talk to a Georgia attorney immediately to determine your rights and responsibilities under GA law.
It may have been a huge mistake to pay money without seeing a lawyer.
If you are liable, the lump sum payment may be a preference that keeps you from filing bankruptcy for a period of time, and may have wasted $2600.
If you are not liable, you wasted $2600.
See a lawyer who handles bankruptcy and such claims (my office does handle these type cases) to see what you should do and stop talking to the insurer. Nothing is more risky than talking with the other side without counsel.
The lack of insurance doesn't affect bankruptcy absent other facts, but the $2600 payment might.
Your friend also may be eligible for bankruptcy. Both of you should see lawyers.