Judge accordingly

What if, we are subject to prosecution for criminal neglect if our child gets a disease such as measles without consultation or vaccination of a medical doctor?

Would it go like this; The prosecution would break down when the doctor in the witness box is asked if the child had got the vaccination, would it have got the disease? It is of course, impossible for any doctor of honour to assume perfect omniscience by answering 'NO' or indeed to pretend to be able to answer this at all. 

Resulting in, the judge on hearing this must acquit us or if they are gullible, accept the doctors stance or the pharmaceuticals bribe and, judge accordingly.