It was his brother that he said this to, after they had finished playing a game and his brother was going off to bed. They mention he has said things of this nature in the past... they have searched the canals (water) in the area. It appears they believe he must be with someone because he is unable to walk long distances (per his sister in interview). He left his phone behind.
My concern is the computer / game. Alicia Navarro, also autistic, also a gamer has been missing from Phoenix (nearby city) for two years.
This is what struck me at first. Similarities. MOO