In a brief comment, someone who claims to have read and commented on an early version of Morris' essay makes to unsubstantiated claims about Morris:
We have no reason to believe that Tom Kuhn threw an ashtray at Errol Morris other than Morris's claim. I didn't know Kuhn very well, but I've asked several who did know Kuhn in the relevant period at Princeton, both students and colleagues, and no one thinks this story at all believable. I've asked someone who professionally knows Morris's work as a filmmaker, and that person said that confabulation was not foreign to Morris's m.o.I say that the first statement is meaningless. How many times have colleagues been shocked to discover that person X always so pleasant and etc was really some sort of a monster in human form? But I agree that we have no evidence; it's just that I think Morris' is being intentionally funny. On the second question, watch the Thin Blue Line. On the meta-question, what do we make of someone decrying unsubstantiated attacks making a series of unsubstantiated attacks at least one of which flies in the face of Morris' work?
If you're the sort of person given to privileging evidence and argument, you might find the attack evidence of a flawed argument. If you're the sort of person who doesn't much care about evidence and given to kowtowing to figures of authority, you might find it persuasive.
As to the whole sub-controversy about Kuhn and the Post Modern paradigm shiftery, this view, that Kuhn misunderstood scientific progress and accidentally did real damage to the notion of scientific truth, is -- I think -- that right one. Not, of course, that Kuhn intended that but intentions like cups, liquids, and lips stain many a vest.