Why the Inaccurate Ending?

I saw Blackbeard for the first time today, and was generally pleased with it until the ending killed it.

            It started out so accurately. How Edward Teach came to power, his conspiracy with the governor of New Provenance, his obsession with Captain Kidd, the Navy's attempt to infiltrate the crew, and all these other really neat details that so many producers miss. Then it got to the battle with the HMS Lynx. This when, in history, Teach takes 21 wounds, three being bullets, and dies when his head is chopped off and flies into the water. This knowledge has me keeping track of Teaches wounds. Two bullets and five sword wounds later, his head is cut off and lands ON THE GROUND behind him! SHAME! SHAME! SHAME! SHAME! SHAME! SHAME!

            I'm going to stop here now to take out my aggression by blasting the crap out of rocks and squirrels that throw explosive acorns. (computer games are really weird these days.)