I don't know what his behavior means but I know you should take it seriously. Twenty years ago I read a book called "The Gift of Fear" which hit upon how often people feel apprehensive then do nothing, and are killed. Most animals simple run when they feel it. Humans talk themselves out of it. A few days ago, a stretch limo/SUV in NY crashed and killed all 18 occupants. At least one texted someone to say, this limo is fucked up. I've heard other occupants did too.
Talk to him and gauge his response. Call his parents if you know them. Or close friends. Don't assume it will go away. You may be in danger, and maybe his people already know he will need help one day.
Talk to him and gauge his response. Call his parents if you know them. Or close friends. Don't assume it will go away. You may be in danger, and maybe his people already know he will need help one day.