Right click on the DK's character portrait, and switch him from aggressive mode to normal mode, so he will not auto attack. Aggressive mode is great for archers, but sometimes melee characters can rush into difficult situations.
Well, I did that a long time ago-when I first learned about doing that--but that damn DK Still attacks anything in sight--Stupid DK---always getting Me sidetracked and compromised by doing that very thing. Fortunately for Me,I was level 12 by the Time did Samuel so i got by with a few heal & Stamina Pots.