Forum:Disputing timelines Aperture Science

So I have this problem with the timelines on this page: http://half-life.wikia.com/wiki/Aperture_Science

In Portal 2, JUST before you get back on the elevator from "Before 80's" science area back to where Wheatley is boss, there's a poster on the wall that says:

"CONDEMNED Vitrication Order 06/15/1961 Do not look at, touch, ingest or engage in conversation with any substance beyond this point."

So, the "retro" test area was condemned already back in 1961. This has a whole lot of contradictions currently displayed on the page link above, for example:

"Caroline (secretary, Johnson's successor; late 1980s - unknown)" She was introduced shortly after you entered the "old area". If the place was condemned in 1961 and the messages were pre-recorded, things don't make sense here.

Cave Johnsons disease apparently then also happened much, much earlier. It was also pre-recorded before the area was considered condemned in 1961, much earlier than the 1974 information on the page. So not only the death from mercury was retconned here.

On the page: " Aperture Science focuses on recruiting homeless people for testing instead starting in 1976. (Propulsion Gel was released around this time too.)"

Apparently this too, was much, much, earlier, perhaps by 20 or even more years.

There's more stuff that seems to be disputed because of this poster on the wall. Anyone has any input on this, am I assuming too much or interpreting this poster wrong? I'd definitely like to hear what you have to say about this.