If the store really wanted to, it could track down the women you had taken a picture of(ofcourse they would have to return to the store). Not all your rights are waived in public. In the way their pictures were used they could definately get a good civil case going on character deflemantion and other accounts. A good enough lawyer might even be able to take you to a criminal court and possibly get you on a sex offenders list. All because the pictures were used in a sexual manner.
Now if you would have denied the entire thing your boss wouldn't have had good enough grounds/proof to fire you nore pin it on anyone or you. There are tons of Toys R Us's in this country and your personal info. is private on the forum. So they would have had no way of knowing it was you without a legal process which I doubt they would have wasted their time on.
Also, if you would have denied everything a lawyer could represent you better, no confession, if the worst came about. Yes, this is a worse case senario.