Maybe I'm getting confused with Iron Heroes also. I'm in Confoundo's game, and for the life of us, we all remember reading a footnote or passage that said something to the loose notion of:
You are considered to occupy the squares you move through until the end of your turn. This would allow a rogue to move from one side of a creature to the other and be considered flanking.
If it is indeed Iron Heroes, does anyone happen to know the passage in question (I don't have the Iron Heroes book).
We were going nuts trying to figure out why we all thought we had read this but couldn't find it!