Why were fists flying on the set of Grey's Anatomy this week? Perhaps McDreamy (Patrick Dempsey) and Dr. Burke (Isaiah Washington) disagreed over a patient's care and started a brawl on the surgical wing? Nope. Maybe Dr. Burke got tired of watching McDreamy behave like a love sick puppy, chasing after Meredith, so he put him in a head lock to prove he's the real man around Seattle Grace? Not exactly. Apparently the brawl was unscripted battle between the actor's egos rather than their alter egos! According to MSNBC, Isaiah Washington was seen with his hand wrapped around Patrick Dempsey's throat during a nasty arguement over tardiness on the set. A witness reported that he "grabbed Patrick by the throat" and said some "disgusting things." Washington's representative told Access Hollywood, "differences are inevitable. They were aired, resolved, and everyone has moved on.†Now that things have cooled off, Isaiah Washington is denying to Entertainment Tonight's Kevin Frazier, that the confronation got physical. "Patrick and I are cool," Isaiah told Kevin in a phone interview yesterday morning. "There was no physicality. Yes we were nose to nose and words were exchanged," Isaiah says. "But then I walked off. We've apologized to each other and the crew. Everything is fine." Hopefully, this little tiff knocked some sense into McDreamy, and we'll see him gain some backbone with Meredith on tonight's show!