Jerry, if you read that testimony, it's pretty flaky. "Fibers that were consistent with Oswald's shirt, could have been, might have been etc." But then again, maybe they planted some fibers on the rifle. I wouldn't put that past them. They planted his palm print, didn't they? It wasn't even his rifle, so how could it be his shirt fibers unless they put them there?
As to why he didn't change his shirt, why did he wear it in the first place when the buttons were missing? You can't account for whacky stuff like that. Oswald was eccentric.
But, I hope you're registering on the fact that for the Dallas police to concoct a bus ride and a cab ride for Oswald was out of the realm of possibility.
If there were any figures in the Dallas PD with advance knowledge of the assassination and complicity therein, it couldn't have been many. Very few. The vast majority of the Dallas PD officers weren't involved. At least, they weren't aware of being involved. But, if they had been asked to concoct a phony story about Oswald, that would have involved them explicitly in the crime. How?
Captain Frtiz: "OK, listen up, men. What we are going to do is frame this Oswald for having ridden the bus and cab. So, we need false witnesses and a bus driver. We also need a cab driver. And let's stick a bus transfer ticket in his shirt pocket- that'll look good. And maybe come up with someone like a former landlady- that's folksy. And I'll tell you what, just have him ride it for a few blocks, and make it the wrong direction- that'll really make him look whacked. And then, let's see, he gets off the bus and tries to take a cab, and he surrenders the cab to an old lady; I love it! The contrast of it all will be great. Crazed killer one minute and boy scout the next. I tell you, I should have been a screenwriter. But chop-chop because time's a-wasting, and you guys have a show to put on. Oh, and by the way, we killed Kennedy- just so you know."
It's ludicous, Jerry. So, Oswald rode the bus and he got that transfer ticket which was still with him when he got arrested. So, he didn't change his shirt. Ralph