<"Clearly, the speaker (in this case, the BBC journalist) did not oblige Annette Cowley to return to work.">
You're stuck in a hole. Tell us something new.
Again: Subjective modality = the speaker's subjective belief state or attitude towards the proposition.
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Since the beginning of this thread, you've been attempting to show that certain, singular, examples of "must" and "have to" use do not follow the line of deontic "must" for subjective modality and deontic "have to" for objective modality. Your action would be fine if we were concentrating on proving that singular examples do not follow that line, but that was not the intent of this thread or other threads of a similar nature here. I have many times said that my view of the subjective vs objective divide in BE modality refers to the principle of general use (in Britain). I have agreed that certain BE speaking individuals do not follow the must subjective/have to objective line and that their use may be either regional, idiolectic, or influenced by AE use. So, I fail to see what it is you are arguing against.
I repost this so we can be clear on my stance, once more:
"A general semantic characteristic of the deontic use of the central modals is that they may all be used to express subjective deontic modality but do not all so readily permit the expression of objective deontic modality, for which speakers tend to prefer to use an alternative, usually non-auxiliary, modal expression. This is the case with must, may and need (the latter in its auxiliary use in negative interrogative contexts). Speakers generally avoid these forms when expressing objective deontic modality, substituting, respectively, have (got to, can/be allowed to and non-auxiliary need to (Cf Perkins 1983:63; Palmer 1986:103.)."
Tendencies are the key in TESOL. If you want to discuss why speakers tend to avoid those forms when expressing objective deontic modality, I'm here and waiting, but to keep looking at singular examples that do not follow the common line, is off-topic and a waste of energy, IMO.