I know exactly what is going on in the video. This actually happened about fifty years ago around where I live, and my grandfather told me about it. This isn't a hoax as much as it is a harmless misunderstanding.
The little man in the video is exactly that a little man, or a dwarf of specific affliction, and significant size. Probably part of a side show act or, a traveling carnival or circus. They actually can make a very good living doing this. Being that there isn't much that a two foot tall person can do.
So here is this guy out taking a walk, and probably having had a couple drinks along the way he finds he needs to relieve himself along the side of the road. When all of the sudden four teenagers stumble upon him scream like lunatics, and scare him half out of his mind.
My grandfather told me that exact story about a buddy of his getting scared shiftless by a side show dwarf. That was with a carnival passing through town. He told me this story after the war of the worlds story. Basically superstitious people in small towns get freaked out really easy.
You guys shouldn't be so jaded, and please did you actually think a ape or a monkey could have pulled that off. Show me such a creature that could actually physically pull that off.