David had no chance in hell against that Klingon
David taking on that Klingon soldier was like a MIT scientist just deciding to take on a highly trained NAVY Seal. He had no chance. He knew it too.
This was very brave and noble, but also very sad. I felt bad for him b/c he had no chance and they played it realistically. Although David manages to tackle the Klingon, he never even lands a single blow, and his killed off quickly.