here are the similar questions I found:
- Question history attributed changes to me that I didn't make
- SO says I made a change that I didn't make
- There is no 5-minute edit window when using the in-page retagging tool
I just want to describe some additional issue.
Here the question I've edited. I saved my edit as 'Code snippets are organized.'. Then I saw that author edited the question and my suggested edit was rejected. As you can see, author's edit summary is ... 'Code snippets are organized.'. However, it contains my changes as well as some code modifications. I guess that our versions were merged. Author's version was applied right away and mine was included in waiting list.
Btw, I've pressed F5 before 'Save Changes'. I'm not sure if it matters.