My apologies. I picked a poor example, and also didn’t explain myself clearly. I’ll try again: in some situations - such as, for example intimate searches or bathing/showering observation in mental health wards - the NHS specifies that only men should search/observe men, and only women should search/observe women. They make a big deal about how important this is. They then, in the same policies, say that trans-identifying men must be searched by women, and trans-identifying women must be searched by men. And that there are no circumstances, including religious belief, under which staff may refuse to do this.
I agree with you, and I think most NHS staff (and indeed their policies) would too, that under emergency circumstances, different instructions would be in play.