[Action]
If Lelouch was on the other side of the war to Guilford it doesn't sound likely they were allies. But a war in the family muddies the waters.
[And here's the apartment complex, but they've already delved into the heart of the subject.]
Are you sure he didn't tell you all of this to get you to act against Lelouch for him? [Lelouch may be a threat, but Josak doesn't know this Guilford well enough to be sure he isn't one. People who want revenge aren't always against using others.]