I (mostly) agree with those as general pointers. But in this case I think the term "mistake" needs breaking down, depending on who it's applied to. Sometimes "mistakes" become so serious, systematic and fundamental to a person/group's politics that it becomes a bit meaningless to talk about "mistakes". Eg we don't refer to New Labour's "mistakes"! Similarly, I think the whole Respect project - to say nothing of siding with Galloway etc - is a major betrayal of socialist politics.
Within that, however, there are further distinctions. Eg the ISG - unlike Galloway, Ridley etc - ARE mistaken comrades. They are socialists who, if they come to their senses, will most likely play a role in any serious left/working-class regroupment. In that sense, my critique of the ISG and my critique of Galloway are very different. I want to try to drive a wedge between the two; I want the ISG to break with Galloway and his bourgeois and petty bourgeois allies.
Talking about Galloway's "mistakes" (the worst version of which is eg the Weekly Worker referring to "comrade Galloway") blurs this important distinction.