It wont, because drama or whatever, but generally when the only reason you can think of for a character to not take a really obvious smart action is "because drama" then you should have gone back to the storyboard and figured out a different situation to be in. Its typically a bad thing when "because the plot needs it" is the only reason you have for characters doing stupid things. If it isn't informed by the characterization (it isn't, Dvalin swore his oath because he is lawful, not because he is an idiot who needs babysitters to make important decisions for him) or forced by outside events (there is no good reason that Dvalin would take a yes vote at face value and, as far as I am aware, no pressing time limit prohibiting an investigation) then a character should not knowingly make a decision against their self interests.