Strange Light Anomaly at the Slave Barracoons: Savannah

I've been trying to upload these three photos for a couple of days now but technical difficulties have prevented it from happening... so FINALLY I get to share these neat and unexplained photos. They were taken a few seconds apart from each other, in the order you see them. I took about a dozen shots of this sport while I was trying to get a good photo to use for my first post about the Slave Barracoons. 

I used the flash in all three shots. I was adjusting my camera settings trying to get the lighting right so I had a couple of seconds of lag time between each frame.

You'll see in the middle of the photos a green light anomaly. It appears to move from left to right. This isn't a lens flair (I'm very familiar with the colors and shapes that a lens flair will create with this camera) nor is it a speck on my camera lens and the green doesn't show up in any of the other many photos I took of this exact same spot.

You'll see that the third photo is a bit out of focus, and the anomaly is actually out of focus just the same!

I have no idea what it is, but I do know that I was completely fascinated with this particular area both before and after learning about it's very dark history. The feeling I got here was indescribable. I felt drawn to it so seeing something show up in my photos is rather eerily expected in a way!