Another situation I've been asked about concerning the new DEC definition is the following:
Nancy has 7 mana open at the end of Abigail's turn and casts
Sphinx's Revelation announcing “Sphinx for 5” Abigail acknowledges this and then during Nancy's untap step realizes that the max it could have been cast for is 4 and calls a judge.
Personally, and correct me if I'm wrong, I'm going to investigate for foul play on Nancy's part but without intent this would be a GRV, correct?