Prior use or even marketing of an invention is not a factor that will make the invention part of the state of the art for novelty purposes.
In other words use or even sale of a product made to a an invention, or embodying that invention, does not make it anticipate a subsequent patent application unless a skilled person could have reverse engineered the product or otherwise out how the invention works.
The disclosure in a document or a prior use is the information that document or use makes available to the skilled addressee. The skilled addressee may be a team.
This was considered in PCME v Goyen Controls Co. UK, where in determining whether the invention had been made available to the public by that device, Laddie J considered what tests or analyses were likely to have been carried out on the product to ascertain how it worked, what would have been the results of those tests and how a skilled person would have interpreted the results.
Furthermore, Purchase L.J. in the Genentech Patent case stated:
…in deciding whether an invention is new within Section 1(1)(a) one must look solely at any matter which has been “made available” to the public. It is an objective question of fact and has nothing with the subjective qualities or knowledge of anyone.
going on to state
The answer to the question: “What is the public?” would appear in a case such as this to be that community of research workers skilled in the art in general but not, I would think, merely known to one or two individual research workers pursuing their own experiments in private.