I know as much about this pic as you do. Just speculating here.
I am very unsure about the time of the happenings in this image, 1979 or 2011?
At first to me it looks almost exactly like the entry passage to the '79 derelict.
But wasn't that slightly tilted with an uneven floor and had no curve at its end?
And as much as I am informed the tunnel was improvised in '79 from salvaged jockey-room/silo-room parts
because they ran out of money,
this would mean that the white-ish plaster bones elements should already be painted and more attached to another at this point.
To me it looks like they have been cast brand new.
The giant black backdrop in the back reminds me a lot on the ones used on the Prometheus set, I think it looks neater than the ones used back in '79.
I see no flared pants and no silly hair.
The guy in the foreground has slightly longer hair which is still quite fashionable for todays standards.
And wearing a hooded shirt over a jacket looks more modern to me.
The ladder looks just like the one in other Prometheus pics (and thausends of other productions).
But what convinces me most is the overall image quality,
the contrast, the colours, the noise, even the lens flare scream cell phone picture to me.
I think a scanned old image/negative would have quite a different feel to it.
Besides I never even remotely saw a picture like this or even of the derelict tunnel set, have you?