Obviously, if Craig had not signed a 'guilty' form, and had instead taken it to court, he would have won, as not enough happened for the cop to 'prove' Craig was guilty of 'soliciting'.
   ...and for 2 months, Craig thought he had made the right choice, since taking it to court would have possibly brought up the same bad publicity and history that he sought to avoid.

The real import of all of this is that Craig does have a checkered past in this sort of thing, and all indications are that he was soliciting and might have attempted further 'activity' if he had not guessed wrong and picked on a cop.

It was a chance thing that someone saw the report and tipped off the paper, and now the whole story...including past allegations...is out.
There was simply no doubt what the Republican party would do once all this hit the media. Craig dug himself a hole for years, saying one thing and sometimes doing another...and he finally fell in it.