Beat him. Plan and simple; Jack would have beat Cal, there's no pregunta about it! He would do anything for her! And we know that cause he gave his life for her:)! And I know Jack wouldn't hurt anybody; but if it was for Rose; he would. Just watch the deleted scene, "Jack vs Lovejoy" and that should pretty much sum up what he'd do to Cal!
I think tu mean "seen" not scene. Well, Jack would probably beaten him but then he'd get caught por Lovejoy and he'd get arrested, unless he's luckily enough to flee with Rose like he did when Cal threatens him por shooting at him with Lovejoy's gun.