PennLive.com reports on this case, in which Talaag Elbayomy was accused of attacking a man who was marching in a Halloween parade (alongside a "zombie Pope"), and shouting "I am the prophet Mohammed, zombie from the dead" [UPDATE: and apparently carrying a sign that said "Muhammed of Islam" on one side and "only Muhammed can rape America"]. UPDATE: The video from the parade is here.
The judge concluded there wasn't enough evidence to convict Elbayomy of the crime, and it's possible that there was indeed inadequate evidence. A police officer reports that Elbayomy had admitted that he grabbed the parader and tried to grab his sign; but it's possible that the judge found this evidence to not be credible enough to prove guilt beyond a reasonable doubt. Moreover, it appears that Elbayomy was prosecuted for criminal harassment, which requires an "intent to harass, annoy, or alarm," and a mere physical attack with an attempt to grab a sign might or might not qualify, see the pen-grabbing discussion in this case. The acquittal itself might thus be justified, depending on exactly what evidence was introduced.