HE MOMENT REMAINS clear. It was late on the last night of the Maryland legislative session and the race track bill that later figured in the trial of Marvin Mandel and his friends was being talked to death on the floor of the Senate. There was a senator out there, standing, mike in hand, denouncing the bill, and when he finished his speech he headed for the lounge, passing the press table, stopping to ask what I thought. I smiled and refused to say. Marvin Mandel would have been pround.

The senator pressed. He took me by the arm and squeezed it. He needed information. He needed all the information he could get to fight this bill. What did I know? What was I hearing? Who owned the tracks? I backed off, retreating, saying something, probably, about how reporters should report and not spread rumors -- something like that. He looked me in the eye and squeezed a bit harder and I told him what I had been hearing: the governor's friends owned the tracks.

How I knew that is something I can't remember. But we all knew it -- all of us in the press. We knew it and members of the Senate knew it and the stableboys down at the tracks knew it and the racing writers knew it and some of them even wrote it. It turns out now that one of the reasons Marvin Mandel is a free man is that no one can prove he knew it. This must bring a smile to Mandel's face He has been more than simply unconvicted, if there is such a term. His whole method of operating has been exonerated.He must have have known all along it would work out this way.

Anyway, the question now is whether the government should take another crack at Mandel and his friends. The initial reaction is to say no, to say that the defendants have been through enough. God, they must have spent a fortune on legal fees alone, not to mention what the ordeal of two trials has cost them in other ways. You can see the real costs on the face of Marvin Mandel.

There has to come a time when the government stops going after a man. There has to come a time when it says enough. There comes a time when repeated trials in themselves represent punishment, a time when only the government can afford to continue the game.

But there is something that galls here and it has to do with Marvin Mandel and how he operates. The once and maybe future governor is not an evil man, certainly not an unlikable man. It is no accident that his colleagues elected him speaker of the House before he was elected governor by the voters. He is the sort of man other men like.

And it is not that he has been a bad governor. He was a good governor, maybe one of the best Maryland has had in recent times, certainly -- and brace yourself for this -- one of the most honest. In Maryland, this is damning with faint praise, but you only have to recall the trial and how the government was looking into the legal equivalent of belly-button lint to understand that they got very litle on him.

No, there is something else and that something has to do with how Marvin Mandel plays the game. He wins by waiting wntil the other side loses. He makes no moves, says nothing, commits himself only when he has to and then never for what you might call moral reasons. He wins any way he has to, way he can, and what this amounts to is the strategy of the lawyer who wins on appeal. This is not a matter of right or wrong, guilt or innocence, but winning and losing, and so what you do is wait. You wait until the other side makes a mistake and if anyone knew that taking a case like this from indictment to appeal was like shipping fine china across the country without a break, it was Marvin Mandel.

It would be the same with yet another trial, only harder this time. The appeals court has enunciated rules that would make proving a crime even harder than it was the first time. There is a difference between justice and vendetta and so it is probably best that Marvin Mandel and his codefendants be given a pass.

But having said that, the mind goes back to that night on the floor of the Senate and how we all knew who owned those tracks. We knew it and Marvin Mandel must have known it, and yet he says he did not. He says, in effect, that his closest friends owned a race track in the state where he was governor and he knew nothing about it. They made it appear as if he was doing them favors and the end result was that he was indicted and tried and convicted and it was all because his closest friends never told him anything. For a while, he stood before the world as a convicted amn, but now the court, having looked at the law, says the conviction is reversed. It is as good a way as any to leave matters. The court says he is no longer guilty.

Common sense says he was never innocent.