Here is the official answer to the treeborn frog question.
Remembering optional trigger effects is part of skill testing within the game. Players may not use visual aids to remind them.
Remembering mandatory trigger effects (such as Sacred phoenix) is
the responsibility of both players, so players are allowed to use
visual aids (such as turning the card sideways) and even notes to
remind them of its effect.
My question in regards to Alex ruling on this is, Are mandatory Triggers the only rulings that both players are responsible for or both optional and mandatory ones. If Optional ones do not have the same wait or serverity of not triggering and resolving as mandatory ones, why is so much pressure put on all optional effects must trigger and resolve even if they are not being used. Will not a optional effect not being allowed to trigger in and of itself change gamestate? Also what is the best call for a situation like this.
Player A plays Sacred Phoenix. Ends Turn
Player B Fissure's it. Sets a face down spell/trap. Ends Turn
Player A forgets Sacred Phoenix. Continues with turn.
Player B wins on the next turn
Player A is filling out the slip and suddenly remembers he forgot the mandatory effect of Sacred Phoenix.
Boasting in front of a judge Player B says he remembered but wasnt going to tell him.
What type of penalty should be applied.
My opinion would be Unsporting conduct: Cheating As he stated he remembered the effect but chose not to maintain game state by reminding his opponent. For records purpose the DQ would be immediatly given however the round results would remain the same with Player B winning the match but dropped and DQ'd before the next round began.