If the Mains Road Department told you that the Regulations say that you must have a thronomister in your Datsun 180B, and then they said, We/I just happen to sell thronomisters ... would you be right in wondering about the validity/need for that Regulation in the first place.
There may very well have been a good reason for the Regulation, but you must not only be fair ... you must also appear to be fair.