Dave also saw KLM964 (PH-JCT) overhead but he was going west not east.
Can you clarify - by "saw" do you mean eyeballed or saw on the screen ?
And likewise did the flight number come from RadarBox or from an ATC transmission ?
Eyeballed it and Flt no from both RB and ATC
Stranger and stranger ...
Flightstats for yesterday definitely reckons KLM964 is a Newcastle-Amsterdam flight - maybe he was lost :-)