This is my first ever try and NCIS, and please be gentle because I've only ever seen one actual ep to date... Blame Kel for this, she made me watch it, talk about it, its all her fault!
Also note, since 'Bete Noir' is the only ep I've ever seen and I have no idea what came before or went after, I'm just assuming there could have viably been other eps where things didn't go down so well that Tony could have come to Gibbs before, If not, well call it creative licence and suck it up.