Actually it's generally customary to protect an arbitrary version, unless there is an overwhelming majority (i.e. only one person versus everyone else). If it's even remotely close, we just protect a random version, so as to avoid continuing edit wars over which version should be protected.
I don't think I have *ever* witnessed an admin protect a page to revistion that person did not favour. So it can't be *totally* random. :) I'd say that the custom is to protect to a the version that gets most votes, if the number of votes one casts is proportional to how much social influence one has. But it is a bad custom. Besides, now you have also received a written *request* to change to the majority opinions version. SlimVirgin also said that she would "allow" other persons than Eyeon to edit the page.