why the howling?

One thing that bothered me about "The Good Shepherd" (reviewed here) is something I wish I'd talked about earlier: the killing of Professor Fredericks (the late, great Michael Gambon). In the scene where Fredericks walks downhill to what he knows will be his death, he approaches a group of men and loudly asks for a light; the men grab him, dragging him off camera... and then we hear a lot of prolonged screaming, presumably as the old man is being butchered.  The screaming goes on for much longer than I would have thought necessary; the movie makes a point of showing that British conterintelligence was, at that period of history, much better developed than US intelligence, so you'd think the Brits would have figured out how to kill an old man quickly, quietly, and efficiently, without the need for all of that horrible screaming. Or were the screaming and the implied messiness precisely the point? What might be the "in-universe" explanation for Professor Fredericks's grisly murder? Not being a very deep thinker, I found the scene to be in somewhat poor taste.

Can any of my readers make that moment more comprehensible to me?