Ian only relaxed when things seemed to calm down and it became apparent that, for the moment at least, there wasn't going to be a second attempt. He didn't believe this was the end, however, if whoever sent this Nem went through the trouble of mutilating her throat to prevent her from speaking they likely didn't have have much confidence in her success, in fact it showed that, succeeding or not, they thought there was a good chance of her getting captured which meant that there was likely another agent here that would report the result of her attempt and possibly act as a backup assassin should she fail...
...of course there was also the possibility that the little Nem is lying and this is all a ruse to get the knights away from the princess.
either way, he kept the thought to himself for the moment, turning to the others and saying "Captain Fanilly, Sir Gillan, I can see to the princess' safety. I'm sure that the party hunting these conspirators could use all the manpower they can get and the princess would feel a bit more comfortable without too many guards hovering around her" both weren't entirely untrue but Ian had a plan with this. If either of his thoughts were correct, even if he was with only one other knight, the low amount of guards might make the other assassin overconfident and they could make a mistake or, if they weren't and there is a group of conspirators, more knights would have a better chance of dealing with what they might find. Right now Ian could just hope that the fact that he was one of the only two in armor and that his Hundi senses were far better than a human's would get them to agree with him.