Webster's New Collegiate Dictionary: paradox (fr. neut. of paradoxos contrary to expectation, fr. para- + dokein to think) 1. a tenet contrary to received opinion. 2A. a statement that is seemingly contradictory or opposed to common sense and yet is perhaps true. B. a self-contradictory statement that at first seems true. C. an argument that apparently derives self-contradictory conclusions by valid deduction from acceptable premises. 3. something (as a person, condition, or act) with seemingly contradictory qualities or phases.
I agree with Novashannon -- I don't see how Daniel dying in 1977 and then being with the Freighter Folk in 2004 could not fit this definition of "paradox." (especially 2A.)
Of course, now if you're going to say "Well, all rules and definitions are non-existant because this is a fantasy TV show and there is really no such thing as time-travel so therefore there is no such thing as a paradox..." well, then, maybe OK. Is that what you guys are saying?
Or... if you say this situation is NOT a paradox, then what would your definition of "paradox" be? (I'm not being snarky -- I really want to know!)