On the same day (9 May 1940) a Dornier 17 of Wekusta 1 Ob.d.L was shot down 20 km east of Wick (
http://forum.12oclockhigh.net/showthread.php?t=64290) a second Dornier was destroyed a few minutes later about 45 km further east. Both aircraft were flying east.
I'd be interested to know the identity of this second aircraft as a 13 Group intelligence report, dated 10 May, implies the two aircraft were accompanied by a third and had earlier been identified flying west across the coast 25 km south of Wick.
Brian