I see the situation as this -
The doctor has asked the lady to remove her veil, the better to understand her, and she has complied.
Her husband has taken exception this and made a complaint.
The husband feels he is right to complain because, if he believes his religious observance means it is inappropriate for his wife's face to be seen by another man other than him, then he will take offence at another man facilitating that situation - regardless of the situation or reasons involved.
The husband has raised a formal complaint which the doctor's employers are duty bound to investigate.
That is where we are now.
An argument that the complaint is excessive can reasonably be offered - but that does not mean that it can be dismissed unheard.
All complaints must be investigated, however frivolous or vexatious they may appear to outsiders, because to dismiss them removes the right of the individual to be heard. If you dismiss this complaint as 'trivial', where do you go when someone accuses a doctor of sexual assault?
Yes, that's more serious, but if you remove the complaints procedure, you have nowhere to go. If you investigate the frivolous, you can investigate the serious, because you have an unbiased approach to complaints, which is essential.
My view is that the complaint will be investigated, the doctor will have no case to answer, and if the GMC has any sense, it will implement a rule that makes the pressence of a female chaperone mandatory for any patient wearing a veil. The chaperone can then remove the veil, and this nonsense will not re-occur.