At least from what I can see in the pictures, that doesn't at all appear to be coming out of the exhaust port. Seems like any fluid leaking out from that area would drip down to the bottom of the header and run down the inside of the pipe rather than running over the top of it as that would be the easiest path following gravity.
Also from the looks of it, the leak occurred when the bike was parked. Set the bike exactly as you found it, with the handlebars positioned the exact same way, and trace and imaginary line from the top of the header straight up and see if you can find anything above it that may be causing this.
One possible culprit could be a leaking tach cable seal. Now stick with me on this one!
A faulty tach cable seal can allow oil to be pushed up inside the cable sheath and leak out where it joins the back of the tachometer. With the bike parked on the side stand and the handlebars turned to the left, this oil could drip down, possibly following other cables or wires, and end up on top of the #1 header.
Anyway, just a thought, and possibly worth checking out.