Yep, we've all been here before.
Shipper points to the driver (who did nothing but back in and close the doors after loading), carrier points at the shipper who made/palletized/loaded the freight.
In the end, it would be fantastic if all loads over 40 000 lbs were scaled after loading to verify weight distribution. Some carriers actually do this for heavier loads and get reworked when there are issues (we ask the shipper to cover driver time getting reworked and it's always approved). We usually recoup the carriers costs and usually the customer is understanding about the charges. It doesn't make holding your freight hostage the right thing to do though. I hope this gets resolved peacefully.
Keep well,
Mike