Happy Birthday, Larry!
“Larry was never a very good Cylon. He just barely passed the quality control tests, and he never did shoot very well. After enduring a lifetime of teasing by the other Cylons, he finally decided to prove his worth by joining the Cylon military, which was hard-up for recruits, what with the war entering its 40th (?) year. Things weren’t much better in the military, where the taunting from the Cylons on the homeworld was nothing compared to the insults he had to endure from the military killing machines. Finally, he scored a combat assignment. Long story short, when he finally did manage to shoot down a human viper, the thought of the pilot escaping was too much, and he decided to end this cycle of humilation right then and there, no matter what the cost.”
http://forum.galacticwatercooler.com/showthread.php?407-GWC-Podcast-69&p=4918&viewfull=1#post4918