The onus is on the prosecution to make its case and charge. Until such time, there's no need for the defence to say or do anything, regardless of how they might view the path this investigation has taken.
In their shoes, 3 years and counting, with so little to show for it, I'd imagine they don't feel the need to say or do anything.
With respect I think it may be possible that you are misunderstanding the tactics being used by CB's team of lawyers who seem to be maintaining a bullish line in Germany but one which is underreported in English speaking tabloids.
They are not feeling the need to do or say nothing but are vociferous in attacking the State Prosecutors' Office as follows
Snip
One could assume, according to the defense lawyer, "that the MM case could develop into Hitler's diaries for the prosecution."
"Indictment of the public prosecutor's office"
Criminal defense lawyer JS, who represents CB. together with FF, even speaks in a "Zeit" podcast of an "indictment of the public prosecutor's office".
It would give the impression that an indictment in the MM case was imminent.
At the same time, it "shies away from making it possible to deal with the alleged suspicion in the prelimina, as it explains to ntv.de.
For the defense attorney JS, this is difficult to understand in this particular case, especially because of the high media presence.
There is "a certain disproportion," he told Die Zeit. And "between the withholding of the files on the one hand and the offensive media policy of the public prosecutor's office on the other".
Die Staatsanwaltschaft Braunschweig ist sich absolut sicher, den Verantwortlichen für das Verschwinden der kleinen Madeleine McCann gefunden zuhaben. Seit mittlerweile drei Jahren plädiert sie auf Christian B. als Täter - allerdings ohne dessen Schuld zu beweisen.
www.n-tv.de