Grading window closes too easily

Some instructor users have reported that the grading window closes "too easily", a misclick outside the window closes it and its content is lost, which could be annoying if a longer explanation for the grading was already typed in.

Possible solutions:

1. Do not close the grading window when clicked outside of it, only through explicitly clicking the Cancel button.
2. Keep and restore the content for the grading window if it is reopened after a misclick.

Option 2 sounds a better solution for me, but this ticker is also open for discussion.