it's not a copyright issue, it's a trademark issue. if you're both in the same industry, the patent office (who controls trademarks, too) will likely award the trademark to whoever was using it first. assuming this guy hasn't already filed.
if you go here
http://tess2.uspto.gov/bin/gate.exe?...ate=79tc2k.1.1 and search for rockatansky nothing comes up. this thing is confusing as fuck though. but i'd say he hasn't filed. maybe you can file quick style and send HIM a cease & desist
good luck bro