yeah, it's when you get truly addicted, that you loose sense of rational judgement on when it's ok to leave work to go kiting... and when you see the leaves moving on trees and the adrenaline kicks in you loose sense of responsibility towards keeping your job... i just hope there aren't any addicted Surgeon kiters, or Pilots...
but if you are not at that stage yet, you can always try
"i've got family emergency gotta leave early", or
"my wife is ill, gotta pickup kids from school", or
"i have terrible headache, gotta go", or
"got appointment with a trady to install new A/C",
and the list goes on...
(just keep a log of which excuses you already used

)