The chief of AOL Inc has apologised in a memo after showing exactly how not to fire an executive.

AOL CEO Tim Armstrong said in a staff memo on this week that he made a mistake in publicly firing an employee in front of a thousand workers the week before. A recording has leaked to the media in which Armstrong is heard laying in to Abel Lenz, a creative director at AOL, explosively firing the executive after telling Lenz to put down his camera. Lenz’ sacking has stuck, the company says.

The internal memo was obtained by the media, in it Armstrong said: “I am accountable for the way I handled the situation, and at a human level it was unfair to Abel.”

Armstrong explained what pushed him to the brink at the meeting, claiming Abel had previously been warned not to record confidential meetings, but “he repeated that behaviour on Friday, which drove my actions,” Armstrong said.

Lenz was tasked with improving the performance of one of Armstrong’s bigger bets to re-invent the company. Lenz was working on the Patch network, a group of sites dotted around the US in a project that cost AOL $150 million. The meeting was reportedly focussed on improving the Patch idea.

AOL, one of the oldest internet companies, is desperate to improve lagging figures from the last few years. The meeting in question was reportedly attended by over 1000 employees either in the room or tuning in online.