Apparently, when DAS instructors are doing their Instructors Test, a trick they sometimes use is to make the assessor do the u-turn twice so that the assessor ends up facing the same way as the trainee instructor.
By using this trick, they don’t have to do a u-turn themselves and potentially faff it up in front of their assessor.
I found that here: http://www.xrv.org.uk/forums/showthread.php?t=16521 on the 4th post - it’s a thread about the test for DAS Instructors 
I was wondering if anyone had ever heard of them translating this practice to the real world (I would of thought they’d find somewhere to park at a 90ish degree angle to the road to avoid either of these options :D)