It's annoying when I'm using Bluetooth with phone in my pocket. I hang up, next thing I know I'm calling back or loosing some of my Icons.
How do I stop the madness?
I was poking around in my settings to see if I saw anything for this but didn't. However, you may find a setting in different dialer that allows you manage screen on/off settings for phone:
...might be worth a shot to look into some of them.