I mean that they know India Knight, and probably her children, as real people, so of course they aren't commenting on twitter. It's not a case of loyalty/not loyalty, its a case of knowing how to treat somebody else as a fellow human being.
There is no reason that they should have to express every thought on every subject on twitter, and certainly no reason that they should have to make a personal statement vis a vis their colleague/friend who has not been accused of anything.