Nowhere in the standard does it say it has to be done out of hours. It does in retailer standards in the UK but not BRC.
This is from the interpretation guideline.
Tests of the withdrawal and recall procedures
The withdrawal and recall procedure must be tested at least annually. It should be emphasised that
traceability is only part of this procedure. The aims of testing the full procedure are to:
• demonstrate that the system works
• highlight any gaps and where the system requires improvement
• demonstrate how quickly the required information can be collated, and thereby corrective action taken,
such as materials being isolated and quarantined
• act as a training exercise for personnel to ensure that clear roles and responsibilities are undertaken in the
event of a real withdrawal situation.
The test of the recall and withdrawal procedure must include verification of the decision-making process,
traceability of raw materials through to finished product, verification of contacts, and timings of key activities.
Records must be kept of tests of the recall and withdrawal procedure and must include a review of the result
of the test and any action taken for improvement.
If the site has had an actual withdrawal or recall which fully tested its recall procedures, then this would be a
substitute for a recall test as long as records are maintained, an analysis of the effectiveness of the recall
procedure is carried out, and any areas for improvement are identified and acted upon.
That said, you have two options, appeal, or test it out of hours. If you appeal, you risk annoying the auditor (sometimes justified), if you accept it will it improve your quality system? Arguably yes. So while I would have challenged this in the audit, afterwards is probably too late.
It was a requirement of some UK retailer standards though last time I worked with them and there are a few options I did to comply. Once I went in on a bank holiday, another time I started the scenario at 6am, another at 5pm. It doesn't have to be 10pm to be "out of hours".