Might it be that the farm is fed from a pole-mounted tx in PNB fashion? In any case, being a rural supply to a relatively large consumer, the LV mains will likely be short and the  risk of loss of neutral or significant N/E voltages will be minimal compared to the apparent mess of the low voltage distribution system in more built-up areas of parts of the U.K. mainland. 
Lots of similar farms here in the north of Ireland. Given the situation you describe, if it the installation was here, personally, I wouldn’t even mention the issue.

Giving a FI code renders the installation unsatisfactory. That could put the farmer in serious difficulty with the company he supplies to. It may mean that any new crop of birds will be delayed resulting in significant expense to the farmer all because of a note in a guidance document!

If you are concerned, do the further investigation yourself and carefully analyse your findings to support any decision on giving a code rather than blind, pedantic obedience to 7671.

Thank you Lyle for your reply. Yes it is a short cable run from transformer to the metering position. I know the likely hood of loos of neutral is very low.  I have come to the decision not to mention it and leave well alone.  I think I am best taking advice from yourself as I'm I right in saying you  may well have been my tutor this time last year for 2391 inspection and testing course at training Solutions ni?

I said could, not would!

Not my decision to make.

Absolutely Sparkingchip, completely agree. Not my decision either. If Adrian was on one of my 2391 courses he will know that I kept my own opinion out of every aspect of the course delivery. However, when dealing with EICRs, I did encourage candidates to carefully consider any codes they might issue and not be a slave to guidance. Whilst guidance is important and reaching out for the opinion of others is often prudent, being confident in one’s deliberations needs detailed understanding of the system under investigation in order to properly evaluate the risks that noncompliance with industry standards might incur.

That requires inspectors to be significantly above average and whilst acknowledging relevant guidance, they should be confident in the independence of their deliberations. That also means they shouldn’t be unduly swayed by old toss pots like me just because I was privileged to have them in my 2391 class! 

Absolutely Sparkingchip, completely agree. Not my decision either. If Adrian was on one of my 2391 courses he will know that I kept my own opinion out of every aspect of the course delivery. However, when dealing with EICRs, I did encourage candidates to carefully consider any codes they might issue and not be a slave to guidance. Whilst guidance is important and reaching out for the opinion of others is often prudent, being confident in one’s deliberations needs detailed understanding of the system under investigation in order to properly evaluate the risks that noncompliance with industry standards might incur.

That requires inspectors to be significantly above average and whilst acknowledging relevant guidance, they should be confident in the independence of their deliberations. That also means they shouldn’t be unduly swayed by old toss pots like me just because I was privileged to have them in my 2391 class!