Revision Cloud

An image that's just surfaced in the Architecture geek world. Typically, when a set of construction documents have been produced for a building, items change. When there is a change, you add a 'revision cloud' around the area that has been revised and you mark it with a date and a number. Clearly some contractor took this revision cloud as a hole in the slab of this job and used a slab-bore to drill holes in this slab on grade. A lot of websites have the picture inverted so that it looks like a hole in a floor above. If this were the case, you'd see the decking and rebar. Because it's a slab on grade, you can see the sand that the slab sits on. Also, the lines that appear to be shadows are simply moisture in the lower part of the slab. I'd hate to see be on a walk-through and come across this!