Just now it happened that both of us, @marmot and I, wanted to make an edit to the same question (https://topanswers.xyz/meta?q=389), he saved his edit prior to me (at 2019-12-09 19:32:55), but I clicked on "edit" before he did, so I got the state the question was in prior to his edit, and after I did my edit and saved it (2019-12-09 19:33:23) I deleted everything he added in the meantime.
There should be some measures to prevent/resolve such race conditions.
Idea on how to prevent those conflicting edits: Branch out the message at the moment one hits edit and if there were edits in the meantime try to merge. If that's not possible show the merge conflicts. This would be similar to git.
This is going to get more important as more people join so we need to start thinking about implementation soon.
I've moved this on to [to a GitHub issue](https://github.com/topanswers/topanswers/issues/16) so work can begin, and will update the post here when it is complete.