Elizabeth Harmon rested her head on her fists and pondered her next move. If she moved her rook, she would leave her knight exposed. It took her twenty minutes before she saw it. If she picked off his bishop in exchange for her two pawns, she could force his king into an exposed position, using her knight to check. She paused, took a deep breath, and pushed her first pawn forward. Before she had time to think, her opponent played a move she hadn't expected, reaching out with its metallic arms and crushing her finger bones to a pulp.

That's how The Queen's Gambit could have played out if robots had been involved, if a chess tournament last week is anything to go by. In an incident described as "some kind of software error or something", a chess-playing robot played the surprising move of crushing its seven-year-old opponent's finger, fracturing bones.

"The robot broke the child's finger," the President of the Moscow Chess Federation, Sergey Lazarev, told Russian news agency TASS on Thursday. "This, of course, is bad."

Lazarev went on to blame the child's eagerness to make a move – and the operators of the machine – for the incident.

"The robot was rented by us, it has been exhibited in many places, for a long time, with specialists. Apparently, the operators overlooked it," he said. "The child made a move, and after that we need to give time for the robot to answer, but the boy hurried, the robot grabbed him. We have nothing to do with the robot."

The child was able to continue the competition the following day, where the robot did not make use of this new move – which while isn't expressly forbidden, is certainly against the spirit of the game.

Chess grand-master Sergey Karjakin told the Guardian that "this has never happened before".

Let's hope Arnold Schwarzenegger has mastered the Sicilian Defense, for the chess robot uprising has begun.