No matter how much perfection manufacturers like OnePlus intend to put on the software part, your OnePlus 2 could still hang for many reasons. A poorly coded app OR an untested modified kernel that you downloaded from XDA, both could lead your OP2 to a awaken dead state, where its screen is on but the is completely unresponsive.
Well there’s an easy way out for such situations. No you couldn’t pull battery on OnePlus 2. Instead, just press the “Power” button for 8 seconds and your OnePlus 2 will be force rebooted.
Once rebooted, your OP2 should be fully responsive again. As a safety measure, we recommended you to uninstall the app that made your OnePlus 2 freeze OR remove the custom kernel which was responsible for the instability.