Actually, Colin, the Crown prosecutors are used to this.
In our system, they don't meet in advance with the witnesses and prepare them, the way commercial lawyers will with their clients or the defence will in a criminal case. The crown attorneys rely on the evidence gathered by the police and simply offer the witnesses to the court. They ask them questions getting them to present their case, and let the defence poke holes at them if they can.
Ultimately, in theory, the Crown doesn't care if a person is found guilty or not as a result of trial. Their job is to put what evidence they have which contains sufficient facts to warrant being put to a trier of fact (judge or jury) to such trier to ascertain guilt or absence of guilt.
The people who should be wary here are the "feminists" who pander constantly that, contrary to human nature and the whole non-verbal realm of communication, consent requires a signed contract entered into after a 50 question questionnaire on intent 5 years down the road (I exaggerate on purpose, please don't crucify me). The Court just reminded them that the issue of consent is not that straight forward that it requires a positively expressed and provable in court "YES", and that human nature is more complex than that where criminal intent is concerned.