Slavoj Žižek explains that painful event.

For Heidegger, Event has nothing to do with ontic processes; it designates the "event" of new epochal disclosure of Being, the emergence of a new "world" (as the horizon of meaning within which all entities appear). Deleuze is a vitalist insisting on the absolute immanence of the Event to the order of Being, conceiving Event as the One-All of the proliferating differences of Life. Badiou, on the contrary, asserts the radical "dualism" between Event to the order of being. It is here in this terrain, that we should locate today's struggle between idealism and materialism: idealism posits an ideal Event which cannot be accounted for in terms of its material (pre)conditions, while the materialist wager is that we can get "behind" the event and explore how Event explodes out of the gap in/of the order of Being. The first to formulate this task was Schelling, who, in his Welalter fragments, outlined the dark territory of the "prehistory of Logos," of what had to occur in preontological protoreality so that the openness of Logos and temporality could take place. With regard to Heidegger, we should risk a step behind the Event, naming/outlining the cut, the terrifying seizure/contraction, which enables any ontological disclosure. The problem with Heidegger is not only (as John Caputo argues) that he dismisses ontic pain with regard to ontological essence, but that he dismisses the proper (Pre)ontological pain of the Real ("symbolic castration").

P. 166

Ouch. Is ontological pain real? Later Žižek opines on Abu Ghraib and Guantanamo (and what doesn't he touch in these 400 pages?), but sadly misses the opportunity to discuss the proper status of ontology as an interrogation technique.  ¶ 7:18 AM