Dr. Craig is a liar.

[SteveII]

What are our choices? 
A) The universe sprang from nothing
B) The universe (or a predecessor) always existed necessarily 
C) God created the universe from nothing

B is difficult to defend because of the infinite regression absurdity. Between A and C, at least you have God as an efficient cause were as A has neither an efficient nor material cause.

Or maybe it was the lizard people. Or a sentient macadamia nut. Or maybe the concept of indoor plumbing created the universe.

I don't think I will ever understand this comeback. The KCA is properly formed, logically sound, not question begging, not equivocating, and not contradictory. The premises of the KCA, if true, infer the cause of the universe (or its predecessor) to be uncaused, timeless, immaterial, personal, and at least powerful enough to bring a universe into being from nothing. This is all it does. It does not get us to the the God of the Christianity and says nothing about other attributes that God might have.

So, how do we get from that to your comeback?