It seems another conclusion is that they hope to somehow continue using these methods to gather more evidence in the future. By sacrificing this bit of evidence

It seems another conclusion is that they hope to somehow continue using these methods to gather more evidence in the future. By sacrificing this bit of evidence they may think they are saving untold oodles of future evidence. The argument maybe a little thin, seems like the judge maybe setting some sort of precedent here which would require them to always reveal their gather methods if they want to enter the evidence.