I strongly suspect that the PAX sabotaged the seat hoping for an up-grade.
A few years ago my wife and three young daughters flew from Sydney to LHR with BA in economy. Once onboard my wife noticed the seats they were sitting on were hot, the entertainment box below their seats we over heating and the crew were aware of the issue. She was happy to sit there but she just pointed it out to the crew. Before takeoff, they were all moved up to business for the entire flight home without any dramas.
The crews see EVERY trick in the book, day in, day out by some PAX to worm their way in to Premium Econ or Business.