Got an LG G5 and quickly learned that they added a "feature" where double tapping each volume button opened a preconfigured application (Camera or QuickMemo+). Even when locked. Phone had to be completely powered off for it not to trigger. Went in settings and disabled that on day two when I saw how many pictures I had of the inside of my pocket.

Some Androids (like mine) won't lock for a few seconds after turning off the screen. It's a nice feature when you press to turn off the screen, and quickly realize you need to do something else. Just turn on the screen and it's still unlocked.

Entering the pattern after it's locked is pretty much impossible though.

I can configure how long that delay should be. IIRC it's int he display/lockscreen menu. I don't like it tho, as I much prefer the device to be locked when I tell it to, so I won't have to care anymore. The fingerprint scanner on the back makes the unlocking trivial though.

But then that means if you put it in your pocket it might suddenly do something because it's not locked yet.

It might, but it hasn't in the 18 months I've been using it. I don't know what the timer is supposed to be, but it seems like something less than 2 seconds. I'm pretty sure I couldn't get my phone in my pocket and press the power button that quickly if I wanted to.

Also, the case adds to the pressure needed to depress the button anyway.