In the midst of getting my basement finished.

Plumber came in to install the sink and toilet but never tested that the outlet the pump was plugged into was live and receiving power (which is wasn't). He flushed the toilet a few times and the pump overflowed causing water to flow on the concrete subfloor and underneath LVT flooring that was just installed. Now there is water underneath the floor and I am worried about mold/warping/other down the line issues

The only reason I knew this happened was because when I went down to check later in the day, the floor has puddles of water seeping up through the LVT seams and called the plumber who said the outlet didn't work and the pump flooded, otherwise he made no mention of this pretty big issue until it was specifically asked.

Spoke to the plumber, who is blaming the electrician (because the circuit was off), but IMO, the plumber should have checked the power supply before testing the system and this is his fault.

I have had a dehumidifier running the past two days, but have no way to ensure the area under the floor is actually dry unless we remove, dry, and reinstall.

Should this area dry out on its own or does it need to be removed to dry out? Will the water seap into the concrete or dissipate through the floors seams?

If the plumber refuses to pay for the remedies, is it worthwhile to call the plumber's insurance company?