The chances of writing the same words is impossible, but the chances of writing the same idea in similar ways is very possible. If the later happens, it may look like paraphrasing.
Moreso, I pointed out that people overtime tends to confuse their original words and/or ideas from adopted ones. This happens to especially great readers, in order to be very sure, it wouldn't cost much to run a plagiarism test before publishing.
I do not agree that not copying from someone else, you can risk the accusation of paraphrasing. Just read the mega stream threads. In your case, you can accuse every second person of paraphrasing. In such topics, one question is chewed on in all convenient ways. Can anyone blame this for this? I think no.
I can also add, as a recent case of multiple plagiarisms: people suffer from greed, get themselves a lot of accounts. Yes, at the first stages they do not violate the rules of participation in bounty companies, but because they have a lot of accounts, they "work", copying texts in the hope of getting merit. This is a true story. Recently, many accounts have been blocked due to plagiarism that was taken from their social networks. Cheater thought that by copying non-technical texts, it would be difficult to track him. But to his regret, he was greatly mistaken.
Every lie has its own sentence.