People bring up the idea of a false accusation because with any criminal case, we want to determine what happened. People are just imagining some of the possible scenarios. Without any details from an investigation or evidence, we're left with nothing to really talk about but what-if scenarios.
The entire point of an investigation is to find out if the allegations are true and determine what happened. The very act of investigating is questioning the allegations. Are you saying that any type of looking into a rape accusation is supporting rape culture and instead no questions should be asked? In your mind should rape allegations even be investigated? Or should they just result in automatic jail time with no trial because god-forbid we support rape culture by playing with the idea that the accused may be innocent?
Unless we get some kind of scientific study that shows that it is 100% impossible for someone to lie about rape, an accusation should be given due process. I'm not even just talking about someone lying about being raped. What if they were raped while drugged/drunk and accuse the wrong person? What if they were raped by someone close to them and accuse another to protect the first party? I'm no detective, but I'm pretty sure there is a good reason why that type of job exists.