You are correct. He was originally charged with Sexual Battery of a Child Sixteen of Seventeen Years of Age, Idaho Stat. 18-1508A. That's a sex crime.
However, he pled guilty to a lesser charge of felony injury of a child, which is not a sex crime. He shouldn't appear on any sex offenders' registry as a result.
We don't know why the prosecutors agreed to the reduced plea. The fact he is only faced with therapy for pornography addiction suggests to me a community with strong teachings against the viewing of pornography. That's about as specific as I'd like to be.
expunged from the records.