If you live your life assuming that anything and everything involving a black person occurs because they are black, and for no other reason - as Diane Abbot does - then you are always going to come up against situations like this.
You shoehorn a racist motive into a situation, and then have to fail to argue that, and that you are incorrect, whihc makes you look naive for your original position, and bull-headed for refusing to accept that you are actually funadmentally wrong in your assessment.
Welcome to Diane's world.
I wouldn't trust her to walk my dog round the block, and I don't have a dog.