I mean, is it? Under his leadership the Labour Party broke the law in relation to racism within the party - that was the finding of the independent Equalities and Human Rights Commission investigation. It found that on Corbyn’s watch, the culture of the Labour Party ‘at best, did not do enough to prevent anti-Semitism and, at worst, could be seen to accept it’. He was the leader, he is accountable. That was his doing.
He then chose to put out a statement rejecting this and dismissing the evidence of racism suffered by Labour members as exaggerated - as a result of which he was suspended. That statement was his doing too.
And now he has chosen to stand against the Labour candidate in an election - this choice was also his doing.
So which part of this is ‘their doing’?
Reminder that the Equality and Human Rights Commission is not ‘the media’. It’s a non-governmental public body created by a Labour government in 2006 to promote and enforce equality legislation introduced by said Labour government.