NEWARK, N.J. (AP) — New Jersey Transit isn't sure it has to pay back the federal government $271 million already spent for the scrapped Hudson River rail tunnel.Executive Director James Weinstein says the state is still in the process of determining what it believes it owes. He says the issues aren't as clear cut as the Federal Transit Administration makes it appear.The FTA on Monday sent the railroad the bill for the so-called Access to the Region's Core project. Gov. Chris Christie canceled it last month, citing cost overruns.Weinstein says NJ Transit is reviewing the request and is assessing its options.