Dr. Craig is a liar.

[SteveII]

You are not understanding the argument. 

1. Whatever begins to exist has a cause of its beginning.
2. The universe began to exist.
3. Therefore, the universe has a cause of its beginning.

In order to avoid an infinite regress, that explanation must be uncaused. This is inductive reasoning. Either argue that the universe is eternal and exist necessarily or that causal principles do not apply. Your conclusion "The universe just happened" is every bit as good an explanation as "My god exists without cause." is not an answer. If you do not have successful defeaters for these, you can inductively reason an inmaterial uncaused cause with enough power to create something from nothing.

The cause and effect principle being leveraged here is a temporal principle.  Each cause must precede its effect in time, which means that the principle cannot confidently be applied outside of time.  So, as we trace the universe back to the singularity and we reach the point where t=0, the cause and effect principle no longer applies.  In fact, our entire understanding of the laws of physics breaks down at this point, so attempting to use the cause and effect principle to explain it is completely unjustified and nonsensical.

You have no reason to think that whatsoever. Don't confuse metaphysics with physics.