Guide kills tarpon

I'm sure many of you have seen this video as youtube says it has over five million views, but just in case you haven't check it out. It involves not an ounce of flyfishing footage, but does include a very large hammerhead eating a BIG tarpon. My question is why would the guide and angler not immediately bust that poor fish off and let him fend for himself? Any thoughts on what these idiots were thinking?