Jose Baez's letter to Circuit Judge Debra Nelson was made public Wednesday.
Baez says prosecutor Bernie de la Rionda was incorrect when he said during a hearing last week that Baez was held in contempt during the Anthony case. The prosecutor was arguing for a gag order on lawyers in the case.
Baez says the only fine he received was for a discovery violation.
A spokeswoman for the prosecutor's office didn't immediately return an email.
Zimmerman is charged with fatally shooting 17-year-old Trayvon Martin of Miami Gardens in February.
Anthony was acquitted of murdering her daughter last year.