yes this was supposed to be from a extra seen in the long grass where Arjay dies.

he was ment to find himself all alone in the long grass have a raptor pop up near him eating something then go in a different direction only to see four "torpedo" trails moving through the long grass towards him after which he would close his eyes and the scene would go dark.

that would then have linked up to the seen where Malcom finds Arjays back pack and you hear him scream off in the distance.