Resolving an ambiguous game state caused by mixing restricted mana
We will start with the relevant rule:


  106.4a If a player passes priority (see rule 116) while there is mana in his or her mana pool, that player announces what mana is there. If any mana remains in a player’s mana pool after he or she spends mana to pay a cost, that player announces what mana is still there.


Anthony would get a Warning for Game Play Error - Game Rule Violation for failing to follow the above rule.  (I can't think of a card that having the {1} would be advantageous over the {G}, but board state is irrelevant for this kind of infraction.)

The fix for this type of violation is to attempt to fix the problem by performing the required action if possible, if that isn't back up the game if possible, and if that isn't possible leaving the game state alone. In this case if caught soon enough the problem can be fixed by Anthony deciding what kind of mana he has, otherwise just leave the game where it is.

If Anthony's opponent did not catch the error soon after it was committed they would receive a Warning for Game Play Error - Failure to Maintain Game State.

At a Regular REL both of the Warning should be downgraded to Cautions, since the point at Regular REL is to educate and not punish for most infractions.