That video got me mad!
The snake they were harassing at the start was the snake that ate the hippo (notice how big it's belly was)
It regurgitated the hippo because it was being severely stressed and hit by those people. Not only did the hippo die for nothing now, but the snake has no meal and who knows what they did to it after the camera stopped.
It was probably a baby hippo it ate a snake can eat one that size.