I'm not really sure how these things work.
I was driving down a residential road where scaffolders were working, and their vehicle was blocking half the road (i.e. blocking my side of the road). I overtook it and was just level with the cabin when an oncoming car tried to drive round me to get by. I stopped and was thinking about reversing and started to think that one of us was going to have to reverse. She moved forward and, got about half way past me, then scraped her car against my rear wheel arch.
The blockage was on my side of the road - but I was completely stationary when she drove forwards and past me.
The damage is minimal to both cars but you never know, she might decide to say it was my fault and claim to have hers fixed, so I'd like to know where the fault lies.