Honestly? I think that what happened is some weird fucker who was on the radar of at least two TLA agencies was local when someone shot the president and both of those agencies immediately went "we can never let anyone found out how utterly incompetent we are, we need to cause enough smoke, dust and bullshit that even if someone reaches the right conclusion about what happened everyone else will have plenty of reason to disbelieve it." I think they executed the easiest coverup in the world because part of their goal was to make sure everyone knew there was a coverup, just not what they were covering up or on behalf of whom. Was Oswald a patsy? Maybe. If he wasn't he made a lot of really bad decisions in the moment leading up to the first shot being fired, then redeemed himself with some shooting that was so heroically accurate and well-drilled that it bordered on impossible with the gear and positioning he had. Did a bunch of people panic and start trying to ratfuck the investigation? Absolutely. Will they wait until everyone involved's great grandchildren are in the dirt before they tell us one honest word about this? Also yes.