The thing that bugged me about Shaw is his statement that Picard violated the P.D. to snog a certain Ba'Ku.
Shaw seems to have a selective memory, because as far as I recall, Dougherty was the one who violated the Prime Directive... Picard and ENT-E were DRAGGED into the situation due to Data rebelling and trying to protect the villagers (which drew them there to begin with - at that point, they started an investigation to see what caused Data to do what he did which led to uncovering a whole conspiracy).
Also, as it turned out, the Ba'Ku were in fact Warp capable... and Picard and his crew were trying to RESTORE state of things on Ba'Ku planet (and in essence upholding the Prime Directive) by removing the interference from the joint So'Na and Dougherty alliance.
Did he interfere? Technically, yes, but I don't think he broke the P.D. He was trying to remove the external factor that WAS in fact breaking the P.D.