I messed up.
In the original post and graphic below, I said that the results were almost certainly influenced by the comments on Facebook. But I had no idea by how much.
Since then, Kenny has run another poll, using a different voting system that allows us to see the way votes are cast over time, and we can see a clear and very strong bias introduced into the results by people’s comments on the Facebook thread.
That means the same thing will have happened in the original poll, and I commented there myself, too – meaning I have to accept that I was part of the problem.