I found the follwoing quote from a "New York Times" article, and have been curious about this situatuion for some time now. I always thought that an 'and' was needed before the 'then', making the sentence read "Farve stayed with his team and then threw..." Is this merely an acceptable journalism shortcut that should be avoided in formal and acedemic writing.
Favre stayed with his team, then threw four touchdown passes in a victory on “Monday Night Football