LOL, it did look a bit thick in the picture as well. you got a like from me for that one.
But seriously they chose poorly there.
Oh look 10 seconds on the internet finds this spray on barrier: https://grace.com/construction/en-ae/Documents/Perma-A-Barrier%20VP.pdf
I'm not saying that's the stuff to use, i'm saying spray on barriers are easily available.
Huge project, poor planning, poor choices, volunteer workers, what could possibly go wrong?