A question that comes to mind is how do we deal with someone who forgot that his card has madness, discarded it into the graveyard, and noticed it only after some time has passed so that it's too late to back the game up?
At first I thought to go by the GRV remedy of “an object is in an incorrect zone” and moving it to the correct zone, but will the madness even trigger at that point if we move the card from the graveyard into exile? And if it does (only by the account of that it was supposed to go there from the hand) I can't see that qualify as “minor disruption to the state of the game”, since suddenly getting to cast a card for the madness cost could have a lot of impact.
So to make a long story short, a warning for GRV (like we used to give when someone forgot to scry) and leave the discarded card in the graveyard?

Edited Zohar Finkel (April 1, 2016 12:43:40 PM)

First off, it is no longer a GRV infraction to forget to scry - it is now covered in the Tournament Shortcuts section of the MTR:

A player who does not Scry when instructed to is assumed to have chosen to leave the cards in the same order.

I'm not an official source, but unless something comes down from on high, my instinct on how to handle this is to treat it as if they had chosen not to cast the card for its Madness cost, and it is in the graveyard legally after making that choice. The only time I would really want to investigate further is if they had some sort of ability that was contingent upon that card going directly to the graveyard (i.e. Jace, Vryn's Prodigy).

Madness has two parts: the exile replacement effect, and the trigger. The player has certainly missed the trigger, and the card is in the correct zone for all cards but ones that exile on resolution, for either choice on the trigger.

There seems to be little benefit to backing up the game just to strand the card in exile and rule that the trigger is missed.

In short, I agree with Casey.

So basically you're saying to treat this as if the player exiled the card and chose not to play it.
Do we penalize in such a situation? Because if that's the case, I see no reason to.
And just a small note - in that case the trigger was not missed, since the triggering event never happened.

And I see this as a common shortcut. Morever: I'm positive that people would do it a lot, and it wouldn't create any problem.

Originally posted by Adam Kolipiński:

And I see this as a common shortcut. Morever: I'm positive that people would do it a lot, and it wouldn't create any problem.

Agreed. No need to overthink this.