In reference to the patent: US8689717
Correct inventorship is critical to the validity of a patent. Fenwick & West have a nice explanation of this: Correct Inventorship.
There is a body of case law about actions to include legitimate inventors who were not listed as such, in which the new inventor acquires independent right to license the patent. Similarly there is case law about inappropriate and incorrect listing of inventors who can be shown not to have contributed, which in some cases can lead to invalidation of the patent.