Law of Corroboration in Sexual offence

As we know that generally there is no law in evidence act 1950 to say that corroboration is needed for sexual offences. However, the court tend to ask for corroboration in sexual offences. why it is so? This is because the judge held that woman involved in sexual offences tend to fabricate some stories or telling lies. From the history, the judge held there are too many cases involve false accusation by the woman. From my personal view, I feel that corroboration for sexual offences are needed even there is no clear provision for this matter. From my experience, I had witnessed a case where a male co-worker had been accused for raping his co-worker in car. After the incident, the victim did not go to the police station to report her case instantly but only being asked by her boy friend to do so then she only went to report the case. I am not sure about the reason, but from I have come out with few inferences:
First: the victim feel ashamed, afraid that this matter will be spread around
Second: the victim actually consent to the sexual intercourse with her co-worker then after found out by her boy friend, and her boy friend felt angry and asked her to do so in order to save face

From the above two reasons I have listed, I seriously feel that corroboration is needed even in a form of documentary or oral evidence is suffice. It is undeniable that the society always hate rapist but don't forget that an accused is always presumed innocent until proven guilty. With corroboration, only the justice could be served.