I could have posted this question earlier but thanks to by bad memory I can finally ask it.
Here's my answer and a competing answer under the same question. At first glance, the first paragraph looks like plagiarism. If you look closely and find revision 3, you'll see I edited a portion into that answer. However later I decided to post an answer of my own, so I took the part that I edited and saved it into my own answer.
In case something similar happens, I would like to know if
I commented on another's answer, they edited into their answer, and later I merge that comment into my answer.
I edited another's answer to add information, later I use that very info in my answer.
Even worse, I remove what I edited into another's answer and put into my own.
Are they considered good, or courteous?