infinity ward guys have been pretty public about their feelings towards treyarch in the past, while treyarch has almost always taken the higher public route by not responding or blowing it off
i've known some of the infinity ward guys are arrogant assholes for a while now, simply by the tone given off in interviews, responses on forums, public sniping at other companies, etc. (some, as i am sure there are plenty of polite people there who quietly did the smh at all that)
if there's any truth to some of the things in the quoted emails, those dudes are sort of fucked