The above screening--which I did not attend (my wife Valarie and I were seeing THE AMERICAN at the Pacific theater in Northridge)--reminds me of a live-music incident from a few years back.
Valarie and I were at the Roxy Theater to see singer/songwriter Nellie McKay (last name pronounced mckie with a long "i") when a drunken audience member began talking to Ms. McKay in a rather infatuated manner. Nellie was wearing a powder-blue prom dress and the inebriated man apparently found her a vision of dream woman loveliness. About the same outcome as the Egyptian Theatre incident occurred (it took several minutes for the Roxy staff to get their act together and eject the audience member), but without any violence and audience members playing at being vigilante security.
A similarity in reactions to the two incidents: people either sat in frozen discomfort (commonplace in L.A.--where folks with abundant money don't want to risk alteration of their safe lives by encounters with random craziness) or actively hooted and yelled for the person to be thrown out NOW!!!
All one can do is to be thankful that the Egyptian attendee didn't brandish a weapon like the man who killed the former manager of the Silent Movie Theatre (at a screening of SUNRISE more than a decade ago) and then ran through the audience before exiting the building (the murderer was later apprehended by authorities).