This was the Atlantic Higlands, NJ to Wall Street ferry and NOT the Staten Island Ferry which has made news before. Apparently this particular ferry has also been in previous accidents.
The linked article says that it may have been traveling close to 12 - 14 knots when it hit the pier. The pier they use is at the bottom of the East River which has a substantial current. I'm going to guess that if they shifted into reverse then the tranny did not engage.
New York City ferry crash leaves 85 injured - CNN.com
Gives added emphasis to the old saying: "Always approach the dock at the speed with which you intend to hit it."