I labeled the statement insane not the person. It's also a common slang to call an opinion insane without it being taken to a level of seriousness that you implied.
Given two sets of data: The statistics and your anecdotal evidence.
The probability of anecdotal evidence being correct must be lower than than the anecdotal evidence being incorrect when it conflicts with the statistics since the statistics come from anecdotal evidence.
Therefore, all other things being equal, if you are presented with data that conflicts with your anecdotal evidence the data has the higher probability of being correct.
Given two sets of data: The statistics and your anecdotal evidence.
The probability of anecdotal evidence being correct must be lower than than the anecdotal evidence being incorrect when it conflicts with the statistics since the statistics come from anecdotal evidence.
Therefore, all other things being equal, if you are presented with data that conflicts with your anecdotal evidence the data has the higher probability of being correct.