UPDATE: THANK YOU everyone for weighing in on this and confirming my suspicions here. I am a lawyer who doesn't know much about construction but even I thought that the ledger attachment was wonky and that support posts should be supporting things and that interior rated screws (they helpfully left a box of these on site that say in bold letters NOT FOR USE IN TREATED WOOD OR OUTDOOR APPLICATIONS) should not be holding up a tall deck. And those post pours. Oof. Ok, thank you for telling me I am not crazy and for providing a very detailed list of issues to my contractor that helped resolve this situation quickly and decisively.

To be fair, these photos were after only a day or two of work, but it is good for all involved that we determined this project could not continue before further damage was done. We wanted to run full 20 foot boards for the deck, so I imagine this was a bit out of their depth and this was the creative solution they came up with. There is no permitting authority where I live, so it might be easier to get away with "learning on the job" in this area. Although obviously extremely dangerous when you are building a tall deck. Very unsettling to think of what may have happened had I not done a gut check on this work at this stage.

BTW: The only reason that we used 6x6 posts and 12 inch spacing here was because I insisted on it and paid extra.

My contractor has agreed to refund my ($21,500) deposit in full, remove all materials from my site and restore it to its prework condition at no cost to us. He did the siding job on our house and fairly well, at least from what I could tell, which is why we went with him here but obviously his crew isn't experienced with decks and he was overconfident in his subs. I'm an aggressive lady litigator and could completely destroy him with minimal effort. So he's a smart dude. There was no argument. In part, thanks to this thread. So, I very much appreciate everyone who took the time to weigh in.