This owner merits being investigated and prosecuted. At the same time, the Mayor of New Orleans also merits an invetigation and prosecution for sending so many to the Superdome and Convention Center and abandoning them there, resulting in deaths also.
The Nurising home owner was offered buses and refused. Nagin had buses and didn't use them. I see little difference.
The people in the nursing home were in "assisted living" and had little opportunity to leave on their own.
The citizens of New Orleans, people served by the mayor, may have been reliant on the mayor for help (his civic duty) but they had to get themselves to any sort of shelter (public or private) on their own.
I agree that there is little difference in the end, but they are different scenarios.
A closer analogy would be the parents who stayed at home and kept their kids in the attic with them. The mayor has means at his disposal but we don't live in a nannystate and require the approval of the mayor to do anything for self-preservation.
The school buses were not used because they were not needed. The CTA used their buses and even those were half empty.