If it were n IconicPCB board there would not have been such a lapse.
We do not make product in larger volumes, in fact we only make prototype and very low volume product.
As such all product is carefully inspected and testeted through the production cycle.
Multilayer cores are visually inspected and electrically tested prior to layup.
The product is electrically tested when finished.
There is one avenue for errors to creep in and that is poorly generated Gerber data.
In the years past some of the cad packages had issues in generating correct Gerber layers.
We use Gerbers in all stages of production and testing hence the possibility of bad boards.
Any issues directly attributable to us and our process would result in a remake of the board.
Typically a 24 to 48 hour response depending on number of layers and copper weight.
In case of faulty product, design information is the first port of call. We have tone ohm like test equipment capable of localising shorts to within a couple of centimeters.
We also have the capability to perform sectional inspection ( excising , potting and visually inspecting the cross section ).
In the years past on one only occasion we had failed and we refunded the cost of BOM and boards to the client.
Back then we only provided bare board testing services, The boards were tested electrically prior to final completion for the PCB shop who wanted to cut costs.
We agreed and faulty boards ended up with the end user.
We wore the cost.
Never again.
I guess You are asking as a prelude to sending us a job?