Pedro Pascal fields questions from "George RR Martin" during a panel at Tampa Bay Comic Con.

 He does not demand a confession for killing Oberyn Martell.  When "George" asks him if he could choose any character for "him" to kill, who it would be, Pedro replies, "no one...enough already" with a look of exasperation and a laugh from the crowd.  

Pedro Pascal is doing this celebrity-status thing "right."  He shares the fans' enthusiasm for the show and his character, and graciously gave honest answers to their questions as if he was hearing them for the first time.  He made a point to notice the cosplayers and compliment their handiwork as well.  He earned some groans when he asked if Emma Frost was "from Frozen..." but was only "joking."  hmm.  

I didn't get any quality video footage worth sharing, but...

Here's a clip of footage from YouTube poster "Yoshi Toob" of the discussion