Your opponent is correct. All you get to do is decide whether to accept
the legal play or not. Once you don't accept the roll, then the
opponent starts the play over.
-michael j zehr
My opinion is that once you told him to make a legal play that you
were bound by that decision. Otherwise every time someone made an
illegal play you could ask them to make a legal play and then decide
which play to accept. This would unnecessarily slow the game down.
Before deciding whether to accept the illegal play one must look
carefully at the possible legal plays that may improve upon the
position.
On the other hand I guess one could make an argument for making
a stronger penalty for making an illegal play since the person
making the play has very little to lose if he just has to take
the move back.
jake_