Depends on the upside and downside of delay, but yes, definitely expect a false trigger on a 30 hour clock. Heck you can easily just pass out and not be online for 30 hours. Trip and fall and get a traumatic brain injury and your doctor may medically induce a coma while you're being treated.
But if that happens, I expect they'd notify my emergency contacts in my phone, or at least my partner would get notified, and she'd tell everyone else who'd need to know.
I mean that's counting on a lot of stuff to happen. Emergency contacts often don't get notified. A car crash that gives you the TBI breaks your phone, or they extract you from the car and your wallet/phone are left in the car and they don't even know your identity on admission until they get the license plate lookup. But if your kidnap risk is high and your risk of exposing the data is low, it's fine I guess. For example I don't have anything to lose from the publication of my hard drive (my main computer security threat would be keylogging my banking passwords etc.) and many others are in that position.
The author of the blogpost didn't mention publishing anything, just sending their parents a link to download credentials and instructions in case they're needed, and how to get to their documents. FWIW, their setup reads like it may well just randomly get hacked, anyway.
Apart from that, emergency contacts usually do get notified where I live, police take care of that, and they have to be involved with any major accident. Phones are sturdy things in
practice, and if not there's my identity card and a card with important phone numbers in my wallet.
And if they didn't, my partner would hardly sit around doing nothing if I randomly disappeared.
Yeah but in all that -- you get in a car crash, police look up your info, go to your partner's house, tell them that you're in a coma in the hospital, he or she freaks out and drives down to the hospital and is sitting next to you in the ICU while that machine beeps every 2 seconds... is everybody going to be on top of their email?
Why would she or anyone else need to be on top of their email in such a case? Wouldn't that be the exact type of emergency where that anti-kidnapping system can safely be ignored?