Here is a theory. We have discussed it 1OOO posts ago, and maybe it has been forgotten.
I do not know too much about phone pings, except there was a VERY famous case here 1O years ago, and all of the suspects, witnesses, even where they all lived aside from the crime scene area, and the police station, and all the businesses involved, all pinged off the same tower. IIRC, same thing for the prosser party area and possibly, not entirely sure, even the Boca area in this case.
What if KR turned off her phone because she was not going to make her extended curfew, and did not want her mom calling and finding out she was driving home alone. That could effect whether she was allowed such permission again.
IIRC, sleuths on here figured out she was not going to make that curfew.
Even before there were cell phones and pings, I would get my curfew extended using a rotary phone, and then hope I could sneak in and not wake her up. I facilitated this by leaving my bedroom window unlocked and just went in that way. Never knew if she knew, but weirdly, she never *woke up*lol.