I'm not much of a TNG guy. Would Picard have sacrificed the Ent-D before interfering with a culture (even a "stagnant" to borrow Kirk's opinion)?
Well, Picard was unwilling to violate the Prime Directive even to keep an entire planet's population from being destroyed. But he was willing to violate it to keep Wesley from being killed.
So I'd say that, despite his preaching to the contrary, Picard's commitment to the Prime Directive ends where the safety of his ship and crew begins.
Thanks for the evidence-based deduction.