In regards to point 1). The parent comment is expressing worry about a statistically insignificant event (framed properly (unarmed, non-justified, non-suicide)) and the following response frames the fear as statistically insignificant. I think this is undeniable and the reason why data is important. Again, this isn't a conversation about whether this is an institutional problem; it's about whether we should live in constant fear of airlines because one airline crashes.
While 2). is a bit more difficult to breakdown. Yes, I think an easy case can be made about cops needing more accountability (for the sake of police generally and society). but do we need institutional change broadly (accountability +) because the police system is racist against people of color? ....Well, that's a claim. That's where data is important and feelings are no longer relevant.