There used to be a test for each candidate that the interviewers used. That was " at the end of a long days flying would I want to have a beer with this person".
It had pretty good results for a long time. There was the occasional lapse ( a well known German who was moved on springs to mind) but generally the guys and girls at KA are a good bunch.
I have a feeling Uk pilot 25 might not have made the grade in the "being sociable" area