I'm contributing skepticism. How many arrests statistically lead to convictions? I suspect it's high, but if it's not, then his statement is untrue. I also don't see how it's obvious that was his intent, as I obviously don't see it as meaning that.
Statistics has nothing to do with it. People should be presumed innocent until proven guilty. I am honestly shocked that this appears to be a controversial assertion.
That makes me wonder whether you were being sincere in your response, and if not, what you thought you were contributing.