Would Palmer and Lee's relationship have been "legal"?

When Vance & Gibbs interrogated Palmer about his relationship with Lee, Palmer asked if he was fired because of it. This made me wonder: was this relationship somehow in violation of NCIS 〜ネイビー犯罪捜査班 rules & regulations? In other words, if Lee didn't do the bad things she did, could her relationship with Palmer have been able to develop without major repercussions for either one of them?