You take a few steps toward the traitorous scum. He takes a look at your armored form and leaps away yelling: "Now, brothers! He's the only one that matters, up now all of you!"

The dying man grabs at his side and looks desperately in to your eyes. Then he lifts a cudgel and whacks it over the head of another lizard raider that was aiming to rise from the water. As a reward for his bravery, he gets an arrow to the throat and falls overboard.

You advance and the assassin leaps back. But alread he's at the end of the boat. No farther to run. You keep your defensive shield up as the archers are clearly targeting you, but not a single one getting past your armor.
-So you chose to get me while the others are now getting an easy path up? Well, you've made a mistake! Your shoelaces are untied.
The half-naked backstabber grins expectantly.

EDIT: What do you do?