I know nothing about the historical case itself, but I do know that show trials (http://en.wikipedia.org/wiki/Show_trial) can and do happen. In that case people can be tried and convicted without evidence. So what you consider trivially true, is trivially false. So we're back to a complex debate in which one person is questioning what they readily admit as the accepted version of events. That's all very noble, but I don't expect Wikipedia or anyone else to just roll over at the first sign of a "debunking" of a controversial event.

I understand what you are trying to say however, you are incorrect. The specific case cited being that the original article made the statement "The prosecution, led by Julius Grinnell, did not offer evidence connecting any of the defendants with the bombing. ... ". This statement while presented as a fact is factually untrue. there is no uncertainty involved. One could argue the quality or value of said evidence but can not deny that said evidence was presented.

Regarding what I consider to be "trivially true" is true. The show trials article itself does not contain a single example of a U.S. court case where the prosecution has "gone to court with zero evidence to present".

Reading the article again, the issue seems to be not very subtle semantics. The student asks how the trial could have happened "without evidence" full stop, Wikipedia made the much weaker claim that there was no "evidence connecting any of the defendants with the bombing". They apparently got convicted for "not preventing" the bombing while being organizers of the rally, which you could easily do without being connected to it, and so no proof of that was required. (You could also read the sentence as meaning presenting no convincing evidence, but that amount of weaseling isn't even needed).