The auto fire section (p90) says as its last bullet point "Regardless of whether your initial roll is successful or not, you can choose to keep rolling dice, one at a time..."
In the example in the sidebar, Sabah gives the GM a Darkness Point to reroll, which seems at odds with the above description.
I don't find it very clear from the text, so the only way I can think this works is that the initial roll of (Attr+Skill) can be rerolled by giving a DP, and then the dice (mentioned in the bullet point) are dice over and above that total, and you can keep rolling and adding until you get a 1, or you decide to stop. Is that correct?