In a DWI/homicide case, the trial court erred by allowing a state’s witness to testify about ingredients and effect of Narcan. Although the state proffered the testimony as lay opinion, it was actually expert testimony. When the state called the witness, it elicited extensive testimony regarding his training and experience and the witness testified that Narcan contains no alcohol and has no effect on blood-alcohol content. Because the witness offered expert testimony and because the state did not notify the defendant during discovery that it intended to offer this expert witness, the trial court erred by allowing him to testify as such. However, the error was not prejudicial.