I bring this up as it has happened a few times now. My edits get rejected because someone else beat me to the punch. Just now it was right in the middle of a review process.
So two key questions:
Is there no locking involved when I have the item for review? (Seems not as it was edited while I was editing)
My "reputation" is tarnished by saying I have edited x posts and y were rejected and some of those rejections are not my fault due to this concurrent edit ability.
As an Example: https://askubuntu.com/review/suggested-edits/123092
Changes are the same because someone else edited seconds before I did.
After thought...
Although I accept the answer, why does it allow me to edit a post that has not been reviewed?
That in my eye makes it a bug.