It may have stopped on the hard stuff, it may also have been more luck than judgement, I think the point s a Virgin 737 is meters from doing damage with no media comment whilst a broken baggage belt is news.
As a passenger I would rather be waiting 15 mins long fr my luggage than sitting in a 737 heading towards the end of the runway.
You are kidding about the passengers not knowing anything was wrong aren't you? I suspect or at least hope the 737 was using max reverse and max possible braking in the conditions.
Any sensible passenger would recognize when turning and seeing no runway remaining, that's if they ad runway left to turn on, that it was close.
Bit like a taxi driver screaming to a halt, all wheels locked up, however stopping prior to the white line t the traffic lights saying, what's the problem, I didn't go through the light!