Knowing your position on the case I understand your point, Anne, but the fact remains that handling matters this way makes the McCanns look bad in terms of public relations. Truth, innocence and guilt are separate matters from how the McCanns would wish to be perceived.
Try to understand them. Tannerman was the only bit of evidence they had and it suited them very well because in the same time Ms Tanner was providing Mr McCann with a golden alibi. All of a sudden this is destroyed by a Crecheman who, fortunately, didn't sound very credible not only on the pyjamas aspect but on local and time topic. Tannerman nevertheless went into smoke.
But it does't stop here.
Tannerman's rival appears to be precisely the man that was possibly identified, being perhaps not Mr McCann but certainly Mr McCann look alike. Of course there had been attempts to shift the alert time forward, after the Smith episode, but many statements show that the alert was earlier, previous to the disappearance.
The McCanns are then, for the moment, a bit trapped on the abductor figure topic, a transitory phase I guess, before the end of this year SY will say they're sorry but..