Although I disagree with the guy you are replying to, I'll let you know that the xG were not how you imagine them. There was a greek sport "journalist" who went through the matches and came to the conclusion that the xG goals would be consistent with the scoring.
I'm linking the video and, although it is in greek, you can go to the photos inside the video which show where the shots were taken from in some of the matches.
Edit: Formatting
Although I disagree with the guy you are replying to, I'll let you know that the xG were not how you imagine them. There was a greek sport "journalist" who went through the matches and came to the conclusion that the xG goals would be consistent with the scoring.
I'm linking the video and, although it is in greek, you can go to the photos inside the video which show where the shots were taken from in some of the matches.
Edit: Formatting