That's a fair assumption but the reason it works is because nobody but staff can directly edit. All revisions need to be approved by hand so even when you're revision someone else's submission, the changes need to be approved before they take effect.
The difference with editing your own submissions is that you can make direct changes to them before they're approved. Once they're live on the site though, you have to submit revisions even to content you uploaded yourself.
The difference with editing your own submissions is that you can make direct changes to them before they're approved. Once they're live on the site though, you have to submit revisions even to content you uploaded yourself.