Redsand Canyon then caleb threw that bottle down and grabbed me by my hair

Ah, that was it. Riley.
It seemed that he may be perhaps a little slow, and needed things to be spelt out for him - or he had the audacity to ignore things that were implied, not direct.
Alas, Derg knew for the future to give details instructions to the boy.

The lad was quick to rise, with a great effort and a soft grunt.
Shit, he'd probably eaten enough for half the pack.
"In your own time, as long as it's done."
Derg wouldn't rush him, especially if he intended on trying to run of which would almost certainly ensue in him throwing up all that good food.