A Dutch journalist managed to join a video call for EU defence ministers, much to his and everybody else’s surprise.

Video posted on Twitter shows Daniël Verlaan, a technology reporter for broadcaster RTL Nieuws, in disbelief as he realises he’s actually managed to jump on the call.

RTL said that Verlaan was only able to do so because of information tweeted by Dutch defence minister Ank Bijleveld, including a photo (since deleted) showing five digits of a six-digit PIN needed to join the call.

In a Twitter DM, Verlaan told VICE World News that spokespeople for the Dutch defence ministry and the EU had told him that it was not possible to join the video call with just the PIN as there was an additional security step, but nevertheless he suddenly managed to join the call while on the phone with a colleague.

“It was really unexpected,” he said.

Defence ministers representing EU members and foreign policy chief Josep Borrell were on the call. When Verlaan joins, Borrell asks, “Who are you?”

After exchanging pleasantries, and as laughter is heard in the background, Borrell asks the reporter if he knew he was “jumping into a secret conference.”

“Yes, I’m sorry, I’m a journalist from the Netherlands,” Verlaan says. “I’m sorry for interrupting your conference, I’ll be leaving here.”

Borrell – apparently in jest but also maybe not? – says that joining the call is a criminal offence, “so you better shut off quickly.”

A spokesperson for the Dutch ministry of defence told RTL a staff member had accidentally tweeted the picture containing information that allowed Verlaan to join the call. 

“This shows once again that ministers need to realise how careful you have to be with Twitter,” said Dutch Prime Minister Mark Rutte.

Never tweet.