In the case of OCR dating, the variable that is changing with time is the ratio of oxidizable carbon to organic carbon.
On earth, carbon is continually recycled by biological processes.
If their calculated age does not agree with expectations they will explain it away and look for something else to give them the age they need.
Specific environmental conditions must be met before meaningful age estimates are possible.
However, every calculated date must be evaluated to decide whether it fits within the accepted chronological framework, or whether it needs to be explained away.
Consequently, the OCR method still needs careful stratigraphic observations and separate carbon-14 ‘dates’ as a check.
On further investigation it was found from people involved who witnessed the procedures that there was a problem with the storage of the samples after they were collected.
The reason the results were considered spurious was that they contradicted the dates obtained by other methods.