I think that Lauda is trying to say that everyone can, by mistake, say something already said by someone else with your own words. That somehow I may say something very close to what Satoshi said in his whitepaper, for example, and be banned for plagiarism for that .
This may be considered plagiarism in an University.... And I agree that it is plagiarism, But not here.
The point is that this is not plagiarism in this forum. Plagiarism is being checked by bots and is only banning, afaik, only word to word copies.
I agree with you, with a lot of common topics being posted as a new one then we will obviously have a lot of similar answers who have been posted in the past. But this kind of plagiarism doesn't exist in the forum or at least set an alarm to hunters as it still counts as their own created post. Mostly the copy pasters who have been banned directly have just copy and pasted the post or added some few words of their own or in some rare cases they just translate a foreign language to an english text to make it their own words, none of them actually create their own post with their own content. Posts that have been directly copy and pasted are obvious as they haven't even change the structure of the sentence .