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
Use the and if you repeat the subject.

",... and then he threw..."
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Is the sentence without the 'and' even considred gramatically correct?
Yes, I'd say so.

But if you repeated the subject, you would need the and.
Why is it considred correct besides the fact that it is often used?
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