The only way for him to involved is to have knocked down Madeleine in his car and because of past history, disposed of and hightailed it away, prove it wrong prosecutor, perfect defence. No evidence of intruder or a breakin in 5a.
If there is evidence to support charging Brueckner regarding Madeleine's abduction, we shall just have to wait and see what defence will be presented on his behalf.
For some reason I don't think it will be the one you suggest.
Not everyone has an apparent visceral need to disprove the presence of an intruder who committed the offence against Madeleine.
Much as no-one tried to pretend Brueckner's American rape victim was wandering the streets and Brueckner didn't illegally invade her home ... of which by the way, I have never seen or heard reports of forced entry.
He left one tiny trace of himself in the villa which was found and retained but which could have so easily been overlooked.