I think it was more that he was saying that this poor man is being villified for nothing more than what amounts to 'poor sexual etiquette' and doing so in a way that suggested that he, and others, were the arbiters of what rape was or wasn't, and that the alleged victims were getting their knickers in a twist about absolutely nothing. I saw it not so much as being about him necessarily sticking up for Assange, nor that he was saying 'she asked for it,' but that he gets to define whether a woman can feel like she has been raped or not.
Tbf it's all a fucking messy business now, with various arguments in support of him often jumping around illogically between saying the women made it all up; they didn't make it up but it's not rape, I should know because I understand what is and isn't rape better than you; and focusing on the Sweden-US extradition thing and why he isn't being questioned in London, and thus tacitly agreeing there is a case to be heard since the allegations have been made. I say illogically, because sometimes the same person will use all three arguments in the same conversation.
And again, to the cause of the anger: for women watching all this play out, who have been victims of sexual assault or who are very aware of the shaming and blaming that goes on every day wrt it, it's a very, very high profile example of how the women who allege abuse are so often the very last people who matter in these cases. In that context, it's very easy to understand why it's an emotive issue.