No, The cannot use it as violation because even though us claimed neutrality, they still had weapons and ammo on the ship
Answer: No
Explanation: The US can not say that they were neutral and say that the Lusitania was a violation of neutrality rights because they had been giving Britain weapons and ammo for their war time efforts so they could not have said that it was a violation due to the fact that the Lusitania itself was carrying supplies.