I don't understand what you are asking.
Are you asking if you have a case to sue Denton County? For what would you want to sue them?
Are you asking if you have a defense to the charge of "false report" if you reasonably believed that what you reported to law enforcement was the truth?
Texas Penal Code on False Report http://www.statutes.legis.state.tx.us/Docs/PE/htm/PE.37.htm
The law regarding false reports requires that you act with the "intent to deceive":
Sec. 37.08. FALSE REPORT TO PEACE OFFICER, FEDERAL SPECIAL INVESTIGATOR, OR LAW ENFORCEMENT EMPLOYEE. (a) A person commits an offense if, with intent to deceive, he knowingly makes a false statement that is material to a criminal investigation and makes the statement to:
(1) a peace officer or federal special investigator conducting the investigation; or
(2) any employee of a law enforcement agency that is authorized by the agency to conduct the investigation and that the actor knows is conducting the investigation.
(b) In this section, "law enforcement agency" has the meaning assigned by Article 59.01, Code of Criminal Procedure.
(c) An offense under this section is a Class B misdemeanor.