If SOCIAL_AUTH_FORCE_POST_DISCONNECT is set to True but a POST is not used, the result is a white page; no disconnect, no error messages. It would be better if this resulted in a 500 with an appropriate error-message or a 405, but describing what happens where social_disconnect* is docced would also help.
The view returns a 405 error code (it's triggered by django require_POST decorator).
.. and you have to read the source of decorators.py to see that, preferrably the source to require_POST too. It should be documented.
Doc about 405 response code on disconnect when forcing POST. Refs #759
Reading source code is a common task, anyway, I've added doc regarding the 405 response code.