Just because Lisker was kind of a jackass to people he didn't know - people who were on the opposing side of an as-yet-undeclared war, I might remind you - does not mean that he couldn't be nice to someone he'd known since he was a young teenager. People can be perfectly nice to members of their own family and other people they know personally, while at the same time not giving a crap, or being actively hostile, to people outside of those circles.