South Korea’s top court Thursday unanimously invalidated the election meddling conviction of a former head of the state spy agency, sending the case back to the lower court.

The Supreme Court did not give a guilty or not-guilty verdict to Won Sei-hoon, who led the National Intelligence Service from 2009 to 2013, citing “errors” in the facts and evidence presented.

“What we need to rule on is whether there was any political intervention or online smear campaign (led by Won) based on facts, but we cannot make a ruling as there are no confirmed facts,” the presiding judge said in the ruling.

The lower court sentenced the ex-spy chief to three years in jail in February for violating the nation’s election laws by meddling in the 2012 presidential election campaign to help then-presidential candidate Park Geun-hye win.

The court found the 64-year-old guilty of “willfully” neglecting an online messaging campaign conducted by his agents to sway public opinion in favor of President Park and against her then-rival Moon Jae-in.

The court recognized that 274,800 messages were illegally posted by his agents, who are required to refrain from political activities under the nation’s NIS law, after Park was nominated as a presidential candidate on Aug. 20, 2012.

In the initial ruling, however, the lowest court sentenced him to two years and six months in prison, suspended for four years, clearing him of the election-meddling charge. It only confirmed his charge of breaching the NIS law by failing to remain politically neutral.

The focal point in the verdict was whether to view the attached file on email messages of a NIS agent as evidence to systemically influence the election results. The email listed 269 Twitter accounts of NIS staff members.

If the file is recognized as evidence, the number of messages posted to back President Park increases, which disadvantages Won in the ruling.

By Ock Hyun-ju (laeticia.ock@heraldcorp.com)