We can’t second guess the reason why a person thinks it is a false positive, especially in the case of a tool that can be used of evil as well as good avast can’t determine intent. avast isn’t in the business of waiting to see if you will use the hammer for good or evil, it might be too late then.
Not too long ago the UK police shot dead a man who had a wooden table leg in a bag, someone thought it was the butt of a shotgun sticking out of the bag and phoned the police. Fear that if you wait too long you might be killed was I believe a huge factor in their opening fire and a court cleared them of blame.
That is after all why they are reporting the FP and they usually give their reason for thinking it a FP. If they indeed installed the file/program, etc. that is why we give the option to exclude it, but you have to investigate it first and that is true of all possibly false positives, otherwise why would the user think it a false positive.
It is also worth considering should also investigate ALL detections to ensure that it was indeed correct, I would but then that’s just me ;D