Thank you to everyone who weighed in on these two rather unusual Maj occurrences.
The first situation, in which Jane called a 4 Bam for exposure, then exchanged a joker from another player’s exposure, then added the joker to make her Kong into a Quint, actually presented a bit of dilemma for many readers. We know that when we call a tile for exposure, we can put up 3 tiles, then put up a fourth tile, then take one back, etc., before discarding. So essentially we can add/subtract and do almost anything (within reason) to our exposure as long as we haven’t discarded. Because of this rule, many people assumed that it was okay for Jane to add to her exposure during her turn. In this context, Jane’s action makes perfect sense. It is however, not allowed, and here’s why: When you call for a tile, you must have (at that moment) all the tiles in your hand needed to make that exposure. You cannot add to the exposure after exchanging a Joker, even if it’s still during your same turn.
In the second situation, in which a 3 Crak was mistakenly exchanged for a joker in a Pung of 2 Craks, and no one caught it until later on in the game, you were all correct – the hand that had the incorrect exposure is dead. Nate, the person who mistakenly exchanged the wrong tile, is not penalized. However, if Nate had tried to exchange a 3 Crak for a Joker in Oren’s exposure of 2 Craks and it was noticed immediately (before Nate had discarded), Oren simply gives the 3 Crak back to Nate, who gives the Joker back to Oren, and no one is penalized.
These situations are thought provoking because they don’t come up very often, and if they’ve never come up in your game before, even the most experienced players wouldn’t necessarily know the official ruling.
I would be interested in hearing about an unusual Maj situation that may have occurred in your game, and how it was resolved.