Over a strong dissent from its chief justice, the Delaware Supreme Court late Thursday upheld a vice chancellor’s decision to allow Energy Transfer Equity to walk away from a once-promising merger with The Williams Cos. Inc. by a 4-1 vote.

Though the court identified errors in the lower court’s analysis, a majority of the high court endorsed Vice Chancellor Sam Glasscock III’s conclusion that ETE did not violate a merger agreement by invoking a tax flaw that ultimately sunk the deal, once valued at $33 billion.