I also get more space when pulling my burley trailer. This is also true if I'm fully within a bike lane. I also put the orange flag on the left side of the trailer.

I have a trailer similar to this one: http://www.bikeshophub.com/wp-conten...s/burley-2.jpg

If I drew a line threw the trailer on the line of the bike frame, I'd guess that ~60% of the trailer sits to the left side (non-driveside) of the bike. Is that what is being argued?