“So what would cause QQ to show these smartphones as being on and online for three days after the crash? Can anyone explain that one to me?”
Let me try this one more time: The only way the phone system can know the phone has been turned off is if the phone tells the system that it is being turned off. If the phone dies or is destroyed it never tells the system it is off. So the system believes the phone is still on. After some default period of never connecting with the phone, the swystem may decide to consider the phone “off”, likely after several days of no contact with the phone.
With the same phone you could just jerk the battery out without going through the proper shutdown and the phone system thinks it’s still on? How about the phone system detecting whether there any signal coming from the phone?
I’d like to see an expert’s opinion on this before I make a decision.