Yes, but what if, for example, the work that he had done prior to beginning that one month's involvement in Cruise was the majority of the IP that GM wants to b

Yes, but what if, for example, the work that he had done prior to beginning that one month's involvement in Cruise was the majority of the IP that GM wants to buy? Would you still interpret it the same way? I have no idea whose IP is in there, at all. Just pointing out that simply stating he did "a month's work" could be quite disingenuous.