In my opinion the photographer owns the copyright, regardless of the circumstances in which it was taken.
If the photographer took the time to set up the camera up on a tripod and ready it for a monkey to press a button then he is the creator and owns the copyright.
If the monkey took it's own selfie and no one owns the copyright, then the photographer has taken this non-copyright image and processed it to create a new image, which he surely now owns the copyright to.
Actually, I would argue that simply pressing a button on an already set up camera is more akin to a trigger than a shutter button, the only difference being the triggers physical location on the camera body rather than a few metres away on the floor.
If the photographer took the time to set up the camera up on a tripod and ready it for a monkey to press a button then he is the creator and owns the copyright.
If the monkey took it's own selfie and no one owns the copyright, then the photographer has taken this non-copyright image and processed it to create a new image, which he surely now owns the copyright to.
Actually, I would argue that simply pressing a button on an already set up camera is more akin to a trigger than a shutter button, the only difference being the triggers physical location on the camera body rather than a few metres away on the floor.
