Defence is using this strategy with EVERY evidence, pretending that there is reasonable doubt if the experts can't exclude 100 %. At first sight this seems to be a clever strategy but if you look at the whole picture, you'll realise that defence does this all the time and that this, altogether, means that there is a reason that so many situations, although not 100 % impossible, are unlikely. The reason is that there is no reasonable doubt. Hopefully jurors at least have a rough idea of statistics...
To be fair they wouldn't be doing their job if they didn't try to show reasonable doubt.
Our justice system would not be very good if the accused didn't have the right to have fair legal representation.