Wait, wait. OK, so this guy shouldn't be on the radio talking about something he knows nothing about, but why are we berating him for assuming that the Big Bang was a bang? I don't doubt that he's representing a large group and a popular misconception.
I bet if you polled the general public, most would think it means an actual bang. A bang is a noise that we all know, it's the most common definition of the word.
Did scientists come up with the name 'Big Bang', or the media? Cause if the former, then perhaps less mockery is in order and more examination of the basics of science communication? If you don't mean a bang, don't say a bang. Most people watch Star Wars and don't question the sound effects they hear in space battles. Most people are science illiterate.
So if there is confusion about what the bang in the Big Bang means, then the problem is that the concept is misnamed, not that the public have misunderstood it.