Once when I loaded a page while I'm online an went offline to read the page, I accidentally hit the 'Edit' button. This started the progress bar for the editor and obviously it got stuck after sometime as it was unable to connect to the network. It was frustrating for me as I couldn't cancel the page load and thus couldn't read the article that I loaded until I got the error dialog.
It would be nice if there was a way to stop the editor from loading while it's being loaded. This would help the readers to proceed with what they were reading quickly when they accidentally hit the 'Edit' button instead of waiting for the editor to load and then cancel the edit operation.
Note: This a copy of a similar topic at the Visual Wikitext editor.