I think it's no bigger risk than having friends, co-workers, customers, or family asking him 'why haven't you gone to the police and cleared yourself, they've put your picture in the appeal'. I've heard that his wife did tell him to make contact with the police, but I haven't seen it confirmed. I think he thought he'd be recognized by people who knew him and he had no other avenue at that time.
This kind of crime - the RISK of something not going to plan, being caught, broad daylight and good weather bringing people outdoors to a popular attraction, two girls to control, the girls screaming, is HUGE. As the convicted perpetrator, we can comfortably surmise he is that risk-taker who indeed came forward.
I think he thought it was a trail cam. The girls are not in the image published. He had his story prepared about watching the fish and his stocks. Libby's recording was done in such a way as to not let him know she was recording. The phone was successfully hidden by Abby, but if he'd known about it he wouldn't have left it there, imo. He didn't know about the phone in February 2017, imo.
If that photo was taken by the girls it's not me.
In other words, if that photo was taken by a trail cam, it's me.