I agree that based on current known ‘facts’, it’s busy for want of a better word.
IMO, JL was not aware of SE interacting with anyone near the end of their call, be it the PO or someone else. I think that because I don’t think he’d have waited until the next evening to raise the alarm.
It’s feasible that the PO (or other) could have tailed SE (either on foot or in a vehicle) and struck when they realised she’d put her phone down.
If it was the PO, they may be more likely to know to turn her phone off. Therefore battery may never have been an issue.
Given we know of no other sightings of her past this point, I think SE was either attacked and hidden/left/disposed of around the area of her disappearance, or coerced or forced into a car and driven away.
Lastly, I don’t think an RTA is involved as, even though it makes a cover up more likely if a PO, I just think this would have been witnessed by passing motorists and/or more evidence of it at the scene.
I think the PO is the perp, and has either attacked on foot in the area, and then exited himself somehow or, more likely, kidnapped her by car.