No he was not a zombie, at least not in the Walking Dead sense.

"Once overcome, Eugene chewed flesh from Poppo’s face, but a later autopsy report found he did not actually eat it."

Perhaps he had just finished watching a zombie movie marathon before or during using the marijuana and THOUGHT he was. More likely what MDinana said, a psychic break.

As for the reporting, news has always been sensationalized, and reporters/news outlets always emphasize getting the scoop and speed of reporting rather than accuracy.