There's also a really simple hack: they can just leave their phone/watch at home. And now even if you or they have an emergency, you can't reach them :)
Yes, that's why it's useful to set rules and consequences based on outcomes instead of effort sometimes it eliminates the possibility of making excuses. If they want to avoid the consequences they can learn to take more seriously double checking to avoid the relevant mistake.
For example, we had this issue -- kid would "forget" the phone and then go out. We set the expectation that if they forgot they had to come straight home or else face a week or two long grounding. Lo and behold they quickly got very good at remembering.
Similar issue with "forgetting" to do all the homework and we followed a similar strategy with some success.
It's a useful technique to combat weaponized incompetence. It's nice and appropriate to reward effort instead of outcomes for new things that are still being learned, but once you know they get it, and if you suspect weappnized incompetence-- try tying an outcome they care about that you're OK with them losing on if need be, directly to the goal, and provide support and model appropriate behavior regarding reminders, todo lists, etc.
Not sure if maybe you misinterpreted my comment backward.
