"Just because Seth Rich downloaded the emails to a USB drive doesn’t mean that the Russians didn’t also hack into the DNC server. And just because the Russians hacked into the DNC server doesn’t mean Seth Rich didn’t also download the emails to a USB device." Exactly. Rich may not have been the primary source, but could have been left holding the bag. Occam's Razor.
"The point is that it was the content of those emails, revealing the corruption of the DNC, that damaged Clinton’s campaign. Neither Seth Rich nor the Russians wrote those emails."
So true.
Actually, Occam's Razor would favor the simplest hypothesis that fits all the facts: in this case, it would favor an internal leak rather than a Russian hack as the source of Wikileaks' information, unless there is evidence that does not fit this theory. There does seem to be evidence that the Russians were monitoring the DNC's server to keep track of Ukranian lobbyists working for the DNC (see
Ukrainian efforts to sabotage Trump backfire: Kiev officials are scrambling to make amends with the president-elect after quietly working to boost Clinton.:
"Almost as quickly as Chalupa’s efforts attracted the attention of the Ukrainian Embassy and Democrats, she also found herself the subject of some unwanted attention from overseas. . ."); but I cannot recall seeing any evidence connecting Russia to the Wikileaks leak, apart from CrowdStrike's uncorroborated claim, which should be excluded by Occam's Razor unless they can produce some evidence to support it, which they haven't done publicly so far.