Table result 3NT=. Lead 7♥
SB has been reading the new laws assiduously and was tempted on Tuesday to rise to barmar's bait and test out the interpretation of "is demonstrably suggested" in 16B rather than the old "could demonstrably be suggested". RR, North, took an age to pass, bizarrely because he could not remember whether he was playing a weak two diamonds or a multi with this partner. SB, South, considered upgrading his hand to a strong NT, but he thought that would demonstrably take advantage of the UI, and therefore he chose 3NT, which could not possibly be a logical alternative. His luck was in when the cards lay favourably. ChCh, West, was unhappy and called the director, and suggested that 3NT, playing his partner for a balanced 11-count, was illegal, even though that was only one of many reasons for a slow pass.
How do you rule?