[quote]Similarly the escrow company would have payed the first half based on an incorrect assessment. Also the proration debited from the seller would have been incorrect (to high). So after that closing happens the seller cannot retreive that overpayment from the county. They have to go to escrow who will then have to go to the buyer to try to get the overprorated amount back[/quote]

That does not sound right.

The treasurer issues a bill based on the old assessment value. The escrow company collects part of the bill from the seller and the rest of the bill from the buyer (prorated based on the exact closing date.) When the next billing cycle arrives, it would appear to me that the treasurer would send two supplemental bills/refunds, again prorated based on the closing date, one to the seller and one to the buyer.