Well - i wouldn’t say “way past his hip”
At full speed - ones hand will drift further back - from sheer force and momentum.
The Idea is, once thumb hits hip, start return of arm swing.
The large forces generated, will drive the arm back a touch further, as shown by assafa. But it’s nowhere near Back like you see the slower guys - whos arms Unlock at the elbow, then re-swing back and back till hand is nearly 1 foot behind them…
On the front footage of Assafa, you can really see him Drive the arms DOWN, and Not Back like most slower guys do. Great footage.
Wish we had Slow Mo cameras of Ben running.