Yes, the driver did stop. He was at my side immediately calling 911 and looking after me. Other than the whole hitting me part, he was a perfect gentleman about the whole thing.
I have never felt unsafe while cycling in Austin, and for the most part, have found drivers to be accepting of the sport.
I will certainly be on my bicycle here again as soon as I heal (and figure out a way to finance a new bicycle while waiting on reimbursement....).