You were right. Ah well. Like you said, progress is progress.

Here is IR's response:

Accordingly, the PR states that the walls and footings have been poured and the inside of the perimeter, the slab is coming. I think what confused everyone is the plastic over the area which will be the floor. They put the plastic down to keep it dry, contractor knew they were going to get some wet weather. So, when asked, and viewing the picture, I assumed the plastic was over the concrete to cure the poured slab. Slab hasn’t yet been poured but scheduled.