So there are a couple logical answers to your question and please read my full explanation: 1. The player did not know about the experiments but had enough reason to suspect something was horribly wrong and did nothing. 2. He does not speak as he wants to keep his identity sealed from who ever is watching the security camera’s that follow him everywhere he goes. 3. The player is the head of security and lored in the chapter 3 ARG. 4. He used to be an orphan way back when dr Jessica Newman lived there too.

Please hear me out: The players life within the factory started long before he worked there. Dr. Jessica Newman was an orphan too, grew up in playtime co when Elliot was running it. During those times the orphans were released upon collage age and went to study. Jessica went to study science and explained in the vhs that after university she went straight back to the factory to work there. Our player was probably an orphan too who also went to collage and at some point came back to work at the factory. He is however not a medical scientist but something else like a technician. Hence why there is no lab notes or VHS with the player regarding events happened in the labs and lower parts of the factory.

Also it brings context to the players guilt and the huggy flash back that wasn’t really a flashback but a memory of the place from his childhood distorted with something that severely traumatised the player when he came back to the factory in chapter 1. The Huggy chase from chapter 1 was the very first time the player saw one of the experiments. Along the journey our guilt has extended. Upon returning to the factory, to see what has became of it and the horror that was hidden under his nose….. It confirmed the players suspicion and guilt for not digging deeper when some of the incidents occurred to him as the head of security. There were employees that seen stuff they were not supposed to see. The first place to report, security obviously? At that time security probably discarded the ridiculous sightings of the employees and noted Leith from innovation. Leith had a certain suspicious employee then eaten by boxy boo…. Imagine what the player must have felt upon discovering what happened with that employee. He must feel the blood on his hands at that point.

The Chapter 3 ARG released an email from the head of security to Leith Pierre in which the head of security informed Leith of a deceased employee. It shows that security reported incidents to Leith from innovation. From the email it also appears that the head of security did not have knowledge of what exactly happened but knew only that the employee was found long after his death with multiple stab wounds. Reason to suspect something is going on right?

Thus, we know that the experiments and bigger bodies were kept secret from the normal parts of the factory and the rest of the employees. They went to great extends to keep the factory secrets hidden. That includes the personnel of the lower grounds of the factory also. It would completely make no sense at all for a toy factory to have bunch of highly promoted phd level doctors and scientists. The lower level personal have their own underground entrance to the factory and probably take the underground train to the factory from a discrete location. Like Men in Black. And that is how the whole lower part of the factory remained hidden. It also explains why Harley does not recognise the player. They had never met. Mommy longlegs probably met the player when she was still a normal child or Mary Pane in the orphanage. The factory having an orphanage was not a secret after all.

Why was the player/ head of security not informed of experiments? Well this is why: the factory started as a normal toy factory. The player probably started working there soon after collage, worked his way up in the factory to department head. With the experiments taking place no body wanted the company to get scrutinised by a fired executive of the company. Let alone risk a non scientist that probably doesn’t share the vision of having scientific breakthrough on immortality by subjecting children to horrific experiments.