Personally I think it was prob a mistake was having 2 ppl at the job. Pressure washing is a 1 man job (Unless you have a twin lance washer),.. it rarely pays to have 2 men on this kind of job.
I used to do it with 1 man pressure washing, the other cleaning the windows, but inevitably there was always someone standing watching for some part of the job and money was lost, so now I do it strictly as a one man operation.
Was it a large area, or was it simply grime that was hard to remove? If the latter, spraying some of this down first will make the job a lot quicker:
http://www.mistral.ie/details.php?code=R1130I also find if there are "Black spots" of algae left behind after washing that instead of taking hours removing them with the pressure washer, a good heavy spray of that chloras after the washing is complete will make them disappear almost instantly, saving hours of work.