Estonia Ghost Picture

Sharp from Estonia sent us this wild picture that has some different anomalies in it. If you look in the red triangle, you can see the face of a person (about in the middle). The question is what caused this strange picture? Is it ghostly? Or is it caused by the flash setting or some other interference? You decide:

"The picture was taken in an empty under-construction building (what was a house of Estonia's famous painter, Jüri Arrak) before it was destroyed. The ghost was there in luck (by accident). Really, I wanted to take a picture of a friend who was close to the ghost in real life. We didn't see it because it was so fast that only my camera caught it."