I'm not sure you actually watched the video. What's clear is that Elliot is hanging back as Brad comes to the first restart line, something Sadler knows he's not allowed to do. Brad brake checks to keep Elliot from getting a run, and may have clutched and revved the engine to throw Sadler off. As they cross that first line, only 2 cars go, and that's Sadler and Dillion. They break away from the outside line, but Brad and Hornish don't. If Sadlers excuse about being pushed is valid for Elliot, it's doubly valid for Brad, because he's the only one that was jacked up by the second row.
IMO, Sadler got screwed by Austin. It's a little odd that Austin keeps pushing Elliot right to the line, but backs off and lets Brad get ahead entering turn 1 even though he gets a clear shot into the turn when Sadler moves down. If Austin felt everything was A-OK, his move is to run the high line and pin Brad down in turn 1. He doesn't, because he knows he will get penalized.
Aren't Austin and Elliot competing for a championship? Didn't that move by Austin result in a 20 point swing in his advantage?
I thought Elliots self serving explaination, video and all, was laughable. He never takes responsability for anything, including not giving the spot back.