I agree.
I can’t speak for the local conditions, I was just making observations. I’d imagine you can’t possibly drill a shaft without slurry. For the novices, slurry is a soupy clay liquid holding the sides up in a drill hole, preventing them from caving in. Concrete is heavy than slurry, pump the concrete in at the bottom of a drilled shaft, the slurry floats on top of the concrete, the hole is filled with concrete as you collect the over flowing slurry -possibly reuse it.
Different places lend themselves better to different techniques, bed rock in Mangatten is very-very shallow. Chicago is known for drilled caissons, bed rock at 60-90 feet. Bed rock in Lousiana delta might be 1,000 feet, not friendly to skyscrapers.
In this case, I would guess, the owner gave a clear message to the construction inspection staff not to increase costs. Fighting with the contractor, they might claim those costs or stick it elsewhere in a change order.
The only inspection was what the owner consider “due diligence” and they were preoccupied with selling two bedroom condo’s at $2.1 million.
Buyer beware!
Fat fingers on a phone...god lord.
=> Manhattan.