On more than one occasion, I have had the wrong order selected when I have printed an order. In history, there is a cancel label choice, but it only requests a refund of the postage.
Perhaps an undo choice which would:
A) Cancel and refund the postage for the printed label
B) Stop the tracking number / store update if it hasn't already synced
C) Place the specified order back into the 'to be shipped' que.