Panic detection mode is quietly featured on Android 7.1 to fight malicious apps
This comes in handy if a malicious app prevents you from leaving it by backing out through its pages. The detection in "panic detection mode" sees that you are trying to exit the app you have loaded. And the speed with which you are trying to exit the app indicates panic on your part. Once the feature kicks in and you're safe at the home page, you can then delete the rogue app that is giving you so much trouble.
While this is certainly handy to have, there is one thing about panic mode that won't necessarily make you feel panic-free. The latest distribution numbers show only .9% of Android users running Android 7.1. The panic detection mode is found on Android 7.1 only, which means that a very small number of Android users have protection from a malicious app trying to keep them from exiting it. By the time that is rectified and a much larger percentage of Android users are running Android 7.1, developers of malicious apps will have already discovered a new way to poison the platform.