"I've wasted enough time on your wild goose chases that if you think she's been killed you can go off and find her."  He was angered by her slapping his face.  She was a young fire cracker who liked to mess with him and he didn't appreciate it.  He had delt with Kobolds before and he knew if they did indeed have Aesa they wouldn't kill her off.  It would be more likely to keep her a hostage.  So if Finna was telling the truth it was nothing to worry about in his opinion.  "She'll be fine.  So you can go look fo yourself if you really think something has happened to her."