Happens to me often: mid-emailing on iphone I move the phone from rosary position (flat between two hands) to grip hold (like holding a baguette).
Why? I am distracted for a sec and need to deal with something in meatspace.
A problem: reeeeeaaaly easy to send a mail or mark one for archive in that grip. Happens often. Annoying.
The phone should know I am not looking at it just then. That it is in micro-sleep state.