@SgtEasyThere's always potential danger in Mass Effect :P
But, using my character as an example once more, he didn't come expecting it to be overly dangerous. In fact, the worse he thought it could be was an Eclipse attack, but he felt that was highly unlikely and thus came. All he has in terms of weapons is a pistol and his Omni-Tool's blade, and he isn't that experienced in combat to begin with, so why expect a bad situation?
He most likely thought it would have to do with something about how he helped construct the crucible or something technology related. But because he didn't know exactly, he took a risk to find out. Though at the moment he would probably be staring at everyone slightly dumbfounded by what has been happening. Either that or joining in on the Ellis hate xD