Nope, Smart TVs perform image recognition on input signals as well, and if your neighbor has not disabled their default ISP open wifi then it will connect to it discreetly. Or someone with an LG phone happens to wander in range then they can collude to relay data back to LG.
I remember when I was displaying downloaded anime to my Roku TV from my laptop and the TV recognized what I was watching. That was an eerie realization.
What happened that lead to you realizing ?