Shorted HV Battery Cells in a 2012 Prius PHV (from Japan)

While connecting the HV battery in my 2012 Prius PHV (Plug-In Hybrid Vehicle from Japan) with my assistant, we accidentally touched our wrenches together, causing a spark that burned my finger. Despite this, I continued and connected the battery. The car turned on but wouldn't enter "READY" mode.

I tested each cell, finding most at 3.54v, but two were at 0v. I’ve attached a photo showing the dead cells. A diagnostic test indicated that the voltage sensor isn't working, likely because it’s receiving no power from the dead cells.

The client is understandably demanding new cells to replace the shorted ones, as the vehicle had no battery issues when it arrived—just a need for dust removal. Please advise on how to address this issue.

 

Thank you! Should I be worried that the voltage sensor is damaged?