Does the bolt on the left rotate when the bike is leaned? Aye, it does.

If you look at the first part of the movie I posted (see 11-12-07 post above) I am testing the joint, leaning the bike on tight turns etc. Actually, now I watch the video, it's not that clear.

Due to the narrowness of the hitch construction, the trailer can achieve a very tight turning circle (trailer can be ~90 degrees to bike), something surrendipitous and completely overlooked in the design process.