It used to be said that much of the M&S red lacy stuff was bought by boyfriends to give to their girlfriends for Valentine's Day....and then the girfriends used to return it and pick something else they actually were prepared to wear instead. Might be true; might have been a smokescreen....who knows.
If JL doesn't accept return on lingerie and swimwear, that would explain the absence of similar reviews on its website, combined with the fact that they don't mention the person's sex either.
M&S's policy is becoming clearer by the day. They know exactly what they're doing.