Same here, problems with OK google before L, now with L and Ok google back on so far no voice problems. I am glad this is back working as I used it frequently.
Turning off "ok google" from any screen has helped several G2's (including mine) and someone with a G3 as well. This may be the same issue several have been having the last week or so.
Re: LG G2 Screen issue. Screen flashes automatically from home to lock, opens and closes apps
The unresponsive screen issue near the top had been a common problem with the G2, there are a few older threads on it. I saw the video, have no idea what that lock screen switching crazy is about.
Several G3 and G2 users have had this issue with multiple carriers. Some report turning of "ok google" detection from any screen may help. I am still testing this on mine.