I know I've seen mention of this before, but I couldn't find the thread, so I thought maybe it was just a comment in another spot.
At any rate;
When you use the drawing tool to draw something, it will appear in the wrong place to any other users who are at a different zoom level than you are (similar to the ping bug)
I tested this out with by having two windows open, changing my zoom level, and drawing something on the map.
The further you're zoomed out, the further it's transposed.
In my screenshot, both of the circles were made in the window on your right. First I zoomed out to 60% and circled Fallcrest. Then I zoomed in to 80% and repeated the process.