"Featured" on HN just a week ago, seems GrapheneOS' "Duress pin" would be very helpful in these cases: https://grapheneos.org/features#duress (https://news.ycombinator.com/item?id=47445931).

Now we just have to wait N years for Android and iOS to get approval from the government to build something similar, that they can market yet somehow screw up enough to not actually help.