This was a comment on the newspaper report when someone asked how it happened
No, there are earlier photos of the boat firmly wedged. This can happen because a brick has protruded from the lock wall over time or a ridge in the wall has developed at a particular height. It appears the owners tried the quite sensible remedy of opening the above paddles slightly and flushing the boat out the lock, but it remained wedged or caught on something so the extra water flooded the boat. It's always sad to see anyone's home and possessions get severely damaged like this, shame on those who think it's funny.