It is a remote possibility I agree but we had a sim. scenario a while back which basically caused a go-around during a CAT3 (runway blocked I think) and the flaps stick at 3 with the WTB brakes on, slats retract as normal. Not a huge amount of fuel left so divert will leave you pretty short with all that drag. Moving the lever back to 3 runs the slats back out and you get a nice "green" conf 3 displayed. As Michelda says, an autoland is a much better (or least worst) option than diverting with the flaps out even if you can get there.
Anything less than conf 3 and you are certainly in uncharted waters which is not a good place to be.
As Bus Driver says some flap faults are going to put you into direct law when the gear goes down so then you are snookered and it really isn't your day. An excellent reason to gas it up when the weather is s**te.
