The sources that support the undershoot theory don't seem to agree on how the aircraft ended up pointing away from the airport
A landing 737 has an awful lot of momentum. As that's scrubbed off hitting the water, it would be almost inconceivable that some of it isn't converted to angular momentum in the process.
If it's an undershoot, doesn't it represent either remarkable flying or remarkable luck that it didn't break up? Although, one of the photos suggests to me it's lost its port winglet.