Read his blog. He admits to contaminating his stove and the surrounding area with americium, radium, and beryllium. Or just look at the accompanying photograph. This is not a man who knows how to conduct experiments safely.
I'd say that if he didn't actually contaminate his kitchen, it's only because he was too incompetent to carry out the reactions properly.
I stopped someone driving by my house just now, luckily before he got very far. With that mass and sufficient speed, he could have done some amazing damage...
We seem to have indications that he was planning on continuing to scale up. If a car had been accelerating toward your house and crashed into a concrete barrier instead that might be a better analogy.
I'd say that if he didn't actually contaminate his kitchen, it's only because he was too incompetent to carry out the reactions properly.