North Korea has announced its Vice Premier for Education, Kim Yong-Jin, was executed by firing squad last month. His crime, according to South Korea’s Unification Ministry, was “slouching during a meeting of parliament in late June presided over by Kim Jong Un.”

This report from North Korea comes via the Wall Street Journalwhich says the capital charge formally leveled against the 63-year-old Vice Premier involved “being an anti-revolutionary element.”

AFP elaborates that Kim Yong-Jin was “denounced for his bad sitting posture when he was sitting below the rostrum” during that fateful parliament meeting, which led to an interrogation that revealed various other “crimes.”

Another source said Kim “dozed off” during a meeting with his dictator, was arrested on the spot, and “intensively questioned by the state security ministry.”

The Unification Ministry also said two other senior government officials have been forced into “re-training” sessions. One of them is Kim Yong-Chol, described by AFP as “a top official in charge of inter-Korean affairs and espionage activities against the South.”

He is also “believed to be the mastermind behind the North’s frequent cyberattacks on Seoul,” and was instrumental in the sinking of a South Korean warship in 2010. Kim Yong-Chol’s re-education is evidently complete, as he is back on duty, and the South Koreans are worried he’ll be tempted to prove himself to the dictatorship by “committing provocative acts.”

Although the Wall Street Journal concedes that South Korea’s reports on North Korean purges aren’t always accurate, there does seem to be a particularly brutal crackdown under way, possibly driven by the recent defection of a top North Korean diplomat, and the earlier defection of an entire group of North Korean restaurant workers who had been living in China.