I have even tried calling every internal method I can find just to see if I CAN fix it manually. I have even been able to make a call to the internal navigationManager._panEnd(event)... which should unbind the mousemove handlers... with a valid event parameter and it still doesn't remove the handlers. Can anyone suggest any kind of fix for this?
To reproduce this, just create a simple web page with an Esri map in the iframe...
Start panning the map then move the cursor off the map iframe and mouse-up. You are stuck.