Maybe I can explain.

From my understanding, black holes are extremely dense collapsed held together by gravity. They grow by taking in more mass, which increases their gravity. However, this intook material, and already existing material within the black hole still hold magnetic properties, and these materials are often tightly packed with other materials they would usually repel. (Think of it as holding two north sides of magnets together). The only thing that keeps these particles from flinging each other apart is the force of the gravity field, which holds everything together. However, black holes lose mass through Hawking Radiation, which means that they lose gravity as well. Eventually, the gravitational force of a black hole will begin to equal or become less than the magnetic forces, in which case the black hole will fling itself apart in a Alderaan-esque explosion.(This process takes a while, however. A LONG while.)

So, in essence, that's how stuff can escape a black hole. Also, there is no universal speed limit.

I recommend "The Universe in a Nutshell", by the way. Not exactly a cosmology book, but it's VERY helpful.