One packs used to happen A LOT a couple years ago. Blumenthal and I fought that battle for months. Big 7 packs like San Diego Plumbers and Dallas Dentist were being wiped out by one-boxes.
Back then it was especially bad because most of the one-boxes were old spam listings or old closed businesses - so dead site, dead phone. Knocked all the legit biz out of the pack and the one result was not even valid to help consumers find what they were looking for.
Now it doesn't happen very often, but when it does it's usually because the domain and biz name are close enough to the query and it's a strong enough listing that Google thinks you generic KW search is really a search for that specific business.
But I agree with James. Get the name edited to real name and they'll likely lose the one-box and hopefully goes back to a 3 pack.