Thanks for the replies everyone. I am going on vertical separation rather than the 5 miles and it did seem a lot closer than 1000 ft above us although it is possible that this was an illusion due to its speed.
ATCO1969 - I made that comment to dissuade anyone tempted into making sarcastic comments just because I am an SLF and not a pilot! I would for example know the difference between a runway, taxiway and apron and the position of a fire truck therein
