He marshals evidence from the investigative file. His conclusions are harsh, but I don't think he misrepresents what is in the file.
He makes inferences from Chief Justice Shirley Abrahamson's hypothetical question to her law clerk — right after the incident — "Hypothetically, what you would do if someone got in your space?"
Why would she ask that unless it was her perception that Justice Bradley had just gotten into Justice Prosser's personal space? Blaska's point is to bolster the credibility of the other 3 Justices who said that Bradley rushed at Prosser. The other 3, unlike the Chief, are seen as allied with Prosser, so adding her perceptions to theirs is significant.
By the way, I think a reason for posing the hypothetical is to test a theory that reasonable people retreat. But the law clerk "responded to the Chief Justice something to the effect that he was 6'4" and young, so he wouldn't have to do much to a person." The law clerk, presumably a reasonable man, assumed that one would do something physical — "an arm block... or something" — to resist or deflect.
Also at Blaska's: the investigator's diagram showing the placement of the furniture and various Justices, showing Prosser had no room to retreat.
Lots of comments over there... including Meade's.