More sophistry. Lincoln decided to start the civil war when he *SENT* the war fleet. The Harriet Lane was merely one of the first to arrive. The rest were still in Transit when Sumter started.
Beauregard's whole intent was to prevent the fort from attacking them at the same time the fleet did. In order to make that happen, he had to attack *BEFORE* the entire fleet showed up.
The term for that is "preemptive attack".
It's what many aggressive nations have claimed as their justification for starting wars.
But history does not usually look kindly on such aggressive nations and that is one reason why, for just one example, that the United States took no blatant military actions against the Japanese before December 7, 1941.
Oh, dear... now did I just hurt your sensitive feeeeeeeeelings?