What are we looking at here?
A co inventor only has to have one creative input on one claim to be required to add his/her name to the patent application. I have no idea of Dameron's input but... for an example, if he used a temperature sensor (claim 11) when Rossi did not, or used DC current when Rossi only claimed AC (claim 5) then I think they would be require to add his name to the patent app.