But hey, now some guy on hacker news says his friend witnessed it...
Or you can go to Wikipedia to find a list of accusations (sourced with articles written by journalists) and evaluate whether you find the claims credible based on the journalists/newspapers/people/accusations involved.
I think it's perfectly okay to claim that all of these people involved are lying and it's just a big conspiracy, but at least provide some arguments to this specific case instead of vague "oh, but can we actually trust words on the internet???".