The killing is thought to have been carried out by Islamically inspired militants who took offence to the French magazine's publication of cartoons insulting the prophet Muhammad, but the Lib Dem leader slammed a caller who suggested things might go a bit deeper.
Caller Omar, from Croydon, said: "The cartoons, you could look at it, were the straw that broke the camel’s back.
"When ministers etc. start talking about what’s happened there, why do they never talk about everything else that’s going on? And then this happens at the end of it.
"I’m sure when you look into these people, they claim to be defending the honour of the Prophet. Was their lifestyle commensurate with people who the love of the prophet, peace be on him?
"You’ll find it wasn't. It’s not just the love of the Prophet which caused this action. It’s a lot more.
"This is always taken out of the discussion and they just focus on the cartoons and it’s just doing a disservice to the reality of how 1.4 billion Muslims around the world feel."
Clegg felt the need to to interrupt, saying: "I cannot express to you how strongly I disagree with you. There can be no excuse, no reason, no explanation.
"They have killed cartoonists who have done nothing more than drawings which they so happen to find offensive.
"Here’s the bottom line, Omar, at the end of the day in a free society people have to be free to offend each other. You cannot have freedom unless people are free to offend each other. We have no right not to be offended.
"That fundamental principle of being free to offend people - and not saying somehow that you have a right not be offended in a democratic, open society such as ours is exactly what was under threat by these murderous barbarians.
"To even suggest, Omar, that there is a rationale, an explanation, a motive that somehow absolves them or sheds greater light on such a horrific, cold hearted, cowardly act, I find outrageous."
After thoroughly schooling the caller, the Deputy PM went on to slam Nigel Farage for attempting to score political points from the massacre.