Now you can edit the reviews and responses you leave for local businesses in Google Maps and Local directly in the local knowledge panel when you expand the reviews. Google has added an "edit" button to reviews or responses you have left directly in this reviews overlay.
This was spotted by @keyserholiday and posted on Twitter by Ben Fisher who shared this screen shot of it in action:
I have confirmed that this is live for me as well. Even for reviews left on other businesses.
Here it is where I left a review for a nearby kosher hamburger place, with an edit button next to my review right in the web results:
Here is what happens when you click on edit, it pops up a menu to edit it:
We will see if it leads to more review edits, I doubt it.
Forum discussion at Twitter.