No, you completely missed the point. If Brennan was the source of the description that went out at 12:45, then why is it not Brennan's description?
Brennan was the only person who immediately after the shooting,at 12:30, who went to a police officer and reported that he'd seen a man aiming a rifle out of a TSBD window.
There was no other person who could have been the source for the description that was broadcast at 12:45. And the description is pretty vague .....It's not a match for Lee Oswald but it is the same basic description that Brennan wrote in his affidavit about an hour later.
This is the description that Brennan's wrote in his affidavit:....
"I did not notice anything unusual about this man. He was in his early thirties, slender nice looking, slender and about 165 to 175 pounds. He had on light colored clothing , not a suit."Dispatcher: The suspect in the shooting is approximately thirty, slender build, height five feet ten inches, weight one hundred sixty-five pounds, reported to be armed with what is thought to be a 30 caliber rifle.