I graphed it att www.coolmath.com/graphit and then zoomed in on your intersection, if you keep zooming in and zooming in you se that all 3 lines dont intersect perfectly at the same point. Could it be because, too some line the values are more precise?? for example :+118.364; then we have: 576.8.....? is it. 576.854?? or 576.751?
You have 3 intersects: Att these points two of your three lines cross.
Hope this was somewhat helpfull.