Here's a pretty well reasoned analysis:
Looks like he had engine issues as soon as he took off and was initially out over the water on the ocean side. He turned 180 to head back to the airport and ended up over land at that point. There were some tall condo buildings on the beach between the road and the water that likely committed him to the road/bridge as he didn't have the altitude to get around them after he turned back.
I'm not second guessing this guy, but I probably would have taken my chances with the water. The guy presenting this makes an interesting point that slow speed ditchings in water rarely result in fatalities.