RichLond: I still haven't seen any offical site anouncing this promotion. But based on the rules I have seen so far your strategy seems to be good. Allthough I think this promo is a dog in terms of time consumption.
The loophole in this promo is that the "continent" definition differs from the OW fare rules. That would enable someone on a 3-Continent OW RTW (Europe-USA-Asia) ticket to go quite cheaply like this:
Madrid-(IB)-Casablanca-(BA)-LHR-(BA)-Tunis-(IB)-Barcelona-(IB)-TLV-(AY)-HEL-(AY)- Africa - (Aer Lingus) -Ireland ....
Same should work for US-Panama.
Not a plan yet but an idea.