There is an aspect of the theory that Oswald acted alone that is often overlooked.
If Oswald acted alone then everyone else working in the TSBD building that day were just everyday working folk going about their daily business, unaware that there was a lone nut in their midst who was going to change history. If Oswald was acting alone there is no reason for any suspicious activity other than that related to the actions of Oswald.
The reality could hardly be any different.
Shelley and Lovelady lie to various investigating authorities, including the Warren Commission, about their movements after the assassination. Seconds after the assassination both men re-enter the TSBD building through the front door and make their way towards the back of the first floor where they area seen by Vicki Adams and Marrion Baker. These movements are reflected in their same-day affidavits but in every subsequent statement they invent a series of movements and timings intended to disguise their actual movements.
As we have seen, Oswald expects Shelley to back him up as his excuse for leaving the TSBD building that day, but is instead thrown under the bus by Shelley.
Shelley is also involved in the incredibly suspicious sequence of events that leads to Oswald being brought to the attention of Fritz. Truly sees some of his men being questioned by the police on the first floor and notices Oswald is not there (it emerges that there are at least three other of 'Truly's boys' who are not being questioned by the police at that time). There is no search for Oswald, Truly simply asks Shelley if he's seen Oswald around. Naturally, Shelley says he hasn't and that's enough for Truly to single out as Oswald as someone who has gone missing and who needs to be immediately reported to the police.
Then we have the late addition to the story of Charles Givens, the man who would change his story for money due to his conviction for drugs. The full sorry saga can be read here -
http://22november1963.org.uk/meagher-the-curious-testimony-of-mr-givens - and, although there is little doubt Givens lied to the Warren Commission, I think this is no more than an example of mundane corruption on behalf of the investigating authorities and is not really connected to the assassination as such.
Unlike the string of lies told by Bonnie Ray Williams. This definitely had something to do with assassination itself. I believe Bonnie Ray saw something in the SN he shouldn't have seen and does everything in his powers to distance himself from being there. In his affidavit there is no mention of the half hour he spent on the 6th floor having his lunch. He leaves the distinct impression he went directly to the fifth floor with Norman and Jarman and was never on the 6th floor. The next day he tells the FBI he was on the 6th floor for no more than 3 minutes. This is a clear lie. Every time he is questioned about it, the time he was on the 6th floor slowly increases - 3,5, 10, 12, 15 and finally 20 minutes - and even this isn't the full amount of time. Not only does he try to downplay how long he was on the 6th, he tries to physically distance himself from the SN while he was up there. SEVEN first responders report seeing his lunch remains in the corner where the SN was, three specifically state that the lunch remains were on top of the boxes that formed the back wall of the SN. However, Gerry Hill moves the remains and it is presumably him who puts them down by a trolley a few windows over from the SN where they are photographed by the Crime Lab. It is clear Williams had his lunch in the SN and is probably the black male Arnold Rowland saw in the SN window. However, Williams testifies that he had his lunch where the remains were photographed and we are supposed to believe he was watching this once-in-a-lifetime opportunity to see the President on a gloriously sunny day through a closed, dirty window.
Then there's the truly bizarre story told by Jack Dougherty. He freely admits he was on the 6th floor just before the shooting and then went down to the 5th floor where he heard a shot from the floor above. He then decides to go down to the first floor for some unknown reason, he never explains. On the first floor he approaches Eddie Piper and asks him if he heard anything and Piper tells him he heard three shots.
So Dougherty goes up to the 6th floor to carry on working even though this is the floor he heard the shot coming from!!His account of his movements is just plain strange, as is the way he never has to explain to anyone what he saw when he was on the 6th floor. Never, in any of his statements or his testimony does he have to explain to anyone what he saw on the 6th floor in the minutes after the assassination. Others who were supposed be on the 6th floor, like Givens and Williams, are subject to an intense barrage of questions concerning what they saw while they were up there. But not Jack.
There is so much that is strange and suspicious surrounding the TSBD building and the assassination. If Oswald acted alone it shouldn't be like this, it should be mundane and boring. Fair enough if someone forgets a few details or mixes things up a bit, that's to be expected with a lot of eye-witness testimony. But that's not what we see. The majority of men who worked on the 6th floor that day make up things that never happened. They deliberately distort the reality of events. How can this be the case if these are just ordinary men going about their daily business?