The bang was an expansion of space, ie. the expansion of the dimension in which something can be placed. It was not an explosion that would have had to overcome the mass of the black hole.
Space does not expand or contract. What 'one foot' or 'one yard' means today is exactly what it meant yesterday and what it will mean tomorrow. All of this junk physics we've been listening to all our lives is in the process of going away. You've even got one guy (Hatch) with a dozen or more GPS patents who claims that GPS runs on Newtonian physics and that they're having to work AROUND relativity, not with it.