ILS I am unfamiliar with the ground plan at Leeds yet know that the controllers at Leeds are as good as any in the country so you would be adviced to allow them to make the decisions. For instance it will only be the controllers who have upto the minute info on the slot situation so the departing 737-700 may of been in the situation where it made no difference. Also the situation you refere to is utilising the runways to their full as well. Also MATS 1 states you should not use a runway as a taxiway so I suggest that you get onto the airport owners. Also on this note how much longer really did the 737 have to wait when it also had to wait for the back tracking aircraft. Again I say it is the controllers decision on the spot to decide on who uses the runway and when.
Flightrider my posts are also aimed at you.