Shortly before the incident, Fava was chatting with an acquaintance, who is also homeless, about "quantum physics and the splitting of atoms," according to prosecutors.
Authorities had said Keller joined in the conversation and, for reasons unknown, got upset. He was accused of picking up his skateboard and hitting Fava in the face with it, splitting his lip. Fava then fell and broke his ankle.
That is utterly hysterical! I've been in seminars and conferences where there were quite heated arguments that went on, but nothing like this. Come to think of it, this would have made such seminars pretty memorable! :)