I have run into a problem with our internal program, but can recreate the problem on the API Samples page here so it isn't anything that I'm specifically doing:
Untick 'edit vertices', 'rotate', 'move' and make sure that 'maintain aspect ratio', 'scale' and 'enable editing' are ticked
Select the poly over South America to show the editing controls
Drag the top-right handle to make the area larger
Drag the lower-right handle, and notice the whole shape has flipped and the 4 edit points are in the wrong place
This can be repeated by dragging any of the other corners before then dragging the lower-right corner, and they all cause a distortion in some way. Sometimes the shape is flipped, sometimes it jumps to a different position on the map. Basically, you have to use one handle throughout your edit otherwise things will break.
This is only a problem when 'maintain aspect ratio' is enabled.
Q: Is there a way to only enable/show one of those scale handles rather than all 4?