Yes, s/he has not properly turned off CEC control, but to be fair, the LG settings are confusing in this regard. I'm not sure if the C7 is the same, but on my C8, if you turn off the HDMI-CEC setting completely, you lose HDMI-ARC audio.
What you need to do instead is turn on HDMI-CEC, which LG calls SIMPLINK, but then go into the HDMI-CEC sub-settings and specifically turn off HDMI device control, which LG calls Auto Power Sync. Then you go to the separate HDMI-ARC setting to make sure it's on. (Note that the HDMI-ARC setting is in the audio section, which is a completely different area of the settings.) Why LG does it this way I do not understand. It would make much more sense to me to just have separate HDMI-CEC and HDMI-ARC settings.
So:
HDMI-CEC / SIMPLINK: ON ---> Auto Power Sync: OFF
HDMI-ARC: ON
BTW, despite this unintuitive HDMI-ARC setting, overall I still prefer WebOS over AndroidTV. I have a Sony Android TV and I hate the OS. The OS is like running an Android phone not surprisingly, slower than it needs to be and more glitchy than a TV should ever be. In contrast, LG's TV OS is much more stable and responsive, and I even like the bean bird remote. I cannot comment on Samsung OS because I don't have a Samsung TV and therefore haven't played with the OS much besides what I've seen in the store.