Pressing the reset button is very slow to restore the top content node to its normal state and appears to slow down others working on the site.  I was able to perform a reset quickly by simply clicking on another node in the tree and then clicking on the top content node.

As an aside on some runs, the link checker (apparently) won't finish. Pressing continue simply returns a page in under one second to "Continue" in an endless loop..........thus the resort to the reset button.