Here's my analysis.
The first 707.34 meters is from a point near where K dropped off A & L to the beginning of the bridge.
The next 414.38 meters is from the beginning of the bridge to a point on the south side of Deer Creek where something was occurring between the killer and A&L, this something is what was 'interrupted'. (This distance includes crossing the bridge, going down the hill, through the bottom land, to a point on the south side of Deer Creek.)
The final 50.64 meters is the distance from that 'interruption' point, across the creek, to that point where the girls bodies were found, and includes the elevation change.
I've measured these distances on google earth, and they seem to fit rather nicely, including the elevation change, as the bank of the creek is high, and thence on the other side of the creek uphill to the final CS area.
A chart in Cecil’s report outlined the recorded movement for Libby’s phone on February 13, 2017:
1:31 pm – 2:08 pm – 1,682 steps (707.34 meters)
2:08 pm – 2:18 pm – 414.38 meters
2:25 pm – 2:32 pm – 66 steps (50.64 meters)
2:31 pm – two-floor elevation change