Generally in the academic world, a head leaving in the middle of the academic year is never seen as a good thing (whether for early retirement or not) and there is usually a story behind it. So whatever the official story is this does seem to be something strange. All the more strange is that the retired head is following mumsnet and posting on this topic.
Anyway after having dealt with Broadhurst and what I consider unethical practices I am not surprised. See from Facebook post. I am sure BH will try to get this deleted.