He could if they don't pay him. That would mean Activision Bungie will have to pay part of the 343 staff to avoid a lawsuit.
Overall Activision is to blame because they know they can make more money by cutting content made by Bungie 2013 while being able to sell by 2014.
English
-
I can't imagine he wasn't doing "work for hire" on the project. Not having that sort of agreement would be a bad idea for any big company.