Well there is some obvious proof. The information from rural counties on the Florida website have changed since her departure. Some global information fields on the website have disappeared since her departure reducing data transparency. These are obvious changes that align with her allegations.
And there cannot be any other reasons why information has changed. Has to be that she was right and stuff is being faked.
Then the state of Florida should explain the reasons and what was changed in a clear & transparent manner. Instead the officials including the governor having been calling the fired employee every name under the sun and making all sorts of claims regarding her behavior -- including slut shaming her. Obviously having your employer make all sort of claims in public about you after you have been fired sets the table for a very sizable legal payout to Rebekah Jones due to public officials violating nearly all the state's employment confidentiality laws. I expect we will see the largest payout in Florida history after a civil trial for violations of the state's employment confidentiality rules come out of this.
Maybe more facts will come out in the trial. I agree, if data was tainted with suspicion then Florida should have explained what happened and what it did (assuming they haven't, I haven't looked for it).