Appropriately for this thread, this was one of the few items Rivero posted on his website about the JFK case. And it is a good example of what some of us have been saying about his tactics.
The claim that Oswald was in the doorway is a very old claim which has been thoroughly checked out. The man is Bill Lovelady. Although he looks similar, there are differences, and if you look at pictures of him and pictures of Oswald beside the picture of the guy in the doorway it is clear. In addition, Lovelady said he was there, his co-workers said it was him, and Oswald was seen elsewhere.
Rivero, if he was as smart as people claim, and "did his homework" like some say, KNEW he was telling a lie with this, but he kept it because it was a good visual piece of propaganda.
Ok...got pic of Lovelady in "your homework" for me to compare.
Note that the usual work attire for most folks in Texas or the south at that time was similar, nearly a uniform, and that there's nothing especially odd in similar jackets showing up in late November.
But if you would like to nose into some interesting details, check out the investigation into a second revolver, similar or identical to Oswald's, used to shoot a Postal Inspector on loan to the Secret Service that day, as well as injuries to one of the Secret Service personnel, who was initially reported as having been killed with the President.