The World War 1 sitcom - written by and starring The Inbetweeners actors Simon Bird and Joe Thomas with Jonny Sweet - originally aired on Channel 4 in September 2011.
Chickens was later picked up to series by Sky1 after Channel 4 declined to commission a full run.
"If I was at Channel 4 and talent had produced my biggest hit in 15 years, I would probably not just order a pilot and stick it out late at night," Murphy said at this year's MediaGuardian Edinburgh International Television Festival.
He continued: "And after it had aired, I wouldn't then not give it a series."
Murphy - Sky's director of entertainment channels - added that he decided to pick up Chickens simply because the pilot "really made [him] laugh".
"Sometimes people over-intellectualise comedy," he claimed. "There is a bit of tradition in British comedy of being very worthy or if it's from a Radio 4 background, it can be very clever-clever.
"People can forget to make you laugh. I pissed myself laughing at Chickens. I was amazed Channel 4 turned it down."
> Edinburgh TV Festival live blog: Stuart Murphy on Sky1, Atlantic, more
Watch the stars of Chickens discuss the show with Digital Spy below: