I'll give the <esc> key a try next time. Thank you.
The issue seems to be that modal windows were not used correctly. The design concept of a modal window was for interactions that must be completed before doing anything else. That means they need to be, and are in good practice, coded such the they are always on top and cannot be hidden. The RM7 program seems to have missed this.
You'll notice that good Mac programs tend to use very few modal windows and then generally only for critical interactions.