Even if the monkey did it consciously, it did it with stolen equipment, on a mission somebody paid good money to go and setup. And of course the photographer set the camera's settings too -- pressing the button is the easiest part.

In fact, lots of nature photographers use "camera traps" with automatic trigger sensor when an animal walks nearby -- which is the same as the "animal pushing the trigger" and nobody seriously suggests those are photos the animals took.

Let say you unintentionally put it in the tumble dryer. Would there be an artistic expression in the picture, or would it merely be functional?

Threshold of originality is a complex gray zone.

> The monkey isn't acting with any real understanding of the creative situation so is just an agent of randomness, like the tumble dryer.

One of the pictures shows the monkey perfectly centered with a friendly smile on his lips. In my opinion a clear indication that he did have an understanding of the creative situation, that he did not just randomly click the button.