I read Choppers descriptin very , very carefully and here's my assessment.
It seems that Choppers post stated he was there on a Saturday.
Chopper also stated the plant operated 24/6, which in my book would include a Saturday.
Yet, if one reads the post of his carefully he alludes to everything but people being in the plant.
In fact, it seems as if the plant was vacant at the time of his visit.
That does not conform with 24/6, making the entire post somewhat less than believable.