As massive, legitimate suspicions about the the accuser are uncovered, we are witness to how the process worked and is still working.
As for the case, perpetrating a crime against a criminal is a relatively safe way to do it. And, as for what appears to be happening here, lies and suspect histories make both of them–the accused and the accuser–vulnerable.
Wall Street Journal article (good expose of the ethics and procedures of prosecutors):
“The day we stop being able to believe people is the day that we can no longer prosecute,” Ms. Iluzzi-Orbon said.
“We triumph with the truth.”
“… detectives’ duty to advocate for a victim.”
http://www.time.com/time/world/article/0,8599,2081364,00.html