(December 31, 2015, 11:11 AM EST) -- TRENTON, N.J. — A liability expert may testify that operators and owners of a theme and amusement part should have warned patrons to wait until everyone was seated before lowering a restraining bar, a New Jersey federal judge ruled Dec. 29, declining to exclude the testimony in a negligence lawsuit (Adrianna Guillen v. Six Flags Great Adventure LLC and Six Flags Theme Parks, Inc., No. 14-2091, D. N.J.; 2015 U.S. Dist. LEXIS 173044)....