I agree with sunman, on how to "keep this from happening, in the first place" :

Pull into field and when done programming (chemical application and type of guidance) THEN make sure you drive FORWARD, just a little, so the ICON points the correct direction. 


Note: I've even had the tractor w/ 3 pt sprayer, roll just a tad bit backwards, and my ICON went the wrong direction, also. {Then I use the "other screen" to flip it back}