Goodness me. Is this thread still going?
This is like a Brexit question, splitting the decision as to CCP or not. Who is telling the truth, who is not?
Having looked through the comments, people have debated the academic side of this rather than the practicalities.
Let me give you a scenario.
A laundry uses pins in supplied laundered protective clothing. We have no alternative (not acceptable, I know, but bear with me, this is a thought exercise).
HACCP team reviews this and decides that despite requirements that pins are removed, there is still a risk, but we have a critical control point metal detector set at 3mm stainless. We all know that a pin in the "correct" orientation can pass through a fully functioning and correctly calibrated metal detector, so, despite the CCP status, we are not making the food safe. This pushes the critical control point back to clothing inspection at intake a new CCP. Everybody happy with that? Of course not. Even if you triple passed the garments through a different metal detector, I doubt any technical person would make that offline detector a CCP, it would be a PRP (or OPRP).
We therefore have an in-line metal detection step that can't function achieve the CCP requirements of guaranteeing safe product and a completely separate metal detector that wouldn't be made a CCP despite it being a better control than the online unit.
Another practical element to this conundrum (but real life this time).
We have a bearing starting to break up and it is putting small fragments of sharp metal into the product flow. Too small to be rejected, they unfortunately go out with product. The pieces get larger until eventually one is rejected and found. Unfortunately we still have no idea where it has come from, despite investigations, and production continues with more small pieces being released (unknowingly) to the consumer. Eventually after a couple more rejections, we find the source.
The metal detector has has allowed us to identify the source but has not prevented potentially unsafe product being despatched.
Does this really sound like a CCP or is the metal detector being used as a monitor (particularly in the days or weeks following the incident)?
To me, both scenarios sound like a monitoring exercise.
I know big pieces would be picked up and rejected, but making a product safe under certain circumstances doesn't make the operation a CCP. Having a metal detector doesn't make a product safe under all circumstances, few circumstances do, (such as achieving a particular Fo value in thermal processing).
All that off my chest, at the end of the day, if you call it a CCP or an OPRP, the steps you take, the controls you have in place are probably the same anyway. Just remember that the responsibility is to make safe food not to argue whether controls are effective or not effective depending on the heading on the instruction sheet.