ACBL club game (real world, not a SB to be seen).
NS are an established good intermediate-level partnership.
EW are a last-minute pick-up; East is of comparable level to NS, West is much less experienced (but not a complete beginner).
The pre-game discussion included an agreement to play "Michaels" with no discussion of what that meant.
North asked about the 2♦ call and was told initially "Michaels"; he asked for clarification and was told "both majors", which should, of course, have been the initial response (assuming the near-universal understanding of the Michaels convention).
It turned out that West's rather fuzzy understanding, which took the director considerable effort to get clear, was that it "usually" showed a the majors but "sometimes" showed a major and a minor (which is sort-of true) and that there was no particular rule that determined when it meant which. She was sufficiently confident in this belief that she promised to contact her teacher after the game for confirmation (knowing her excellent teacher, West is doomed to disappointment in this quest).
East and West were both adamant that they had an agreement; unfortunately, they could not be persuaded to agree what agreement they had.
To further muddy the waters, West did not explain before the opening lead that partner's explanation did not conform to her understanding.
The table result was 4♠ making four. NS contended that they would have defended differently had they received a correct explanation; South said that he discarded too many diamonds, which may well be irrelevant. The opening lead was a heart (hoping to set up a ruff for South); South won the Ace and returned a heart for North to ruff.
The double-dummy result in spades on the hand is 9 tricks for East-West; two other pairs in the same flight played the hand in spades (2♠ in both cases); one made 9 tricks, one made 10 tricks.
There is enough happening here that I think it is an interesting case, though the final ruling seems straightforward (I have been surprised in this respect before, however).