Primary sources

I submitted an assignment recently about primary sources re: Charlemagne's coronation (800CE). I was happy with my mark but the assignment made think of how we would analyse primary sources about events that happened more recently. Imagine trying to find the truth about the stabbings at Bondi Junction Westfield over a week ago. For starters, social media and traditional media sources had it wrong in the first instance. Muslims were blamed then a Jewish man was singled out (he is in the process of taking the matter to court). The perpetrator turned out to be non-religious and a white Australian with no organisational connections. Given the misinformation happening at the time, what would someone in 500 years come up with if they studied the issue? Hopefully they would do so with a critical analysis.