I assume there's no possibility that he simply forgot those items ..... There has to be some sinister motive ...right?
Sure there is a possibility. It is just that the more of these "coincidences" one has, the less believable it is that they are "coincidences".
Andy, Would you believe that there was nothing sinister about the act of Leaving $170 and his wedding band in the tea cup?
What would it take to convince you that IF ( I ask IF??) Lee actually left the items there that it may have been the act of an intel agent who knew that he was embarking on a very dangerous mission ....One in which he might not return.
I'd ask you to recall the note he left for Marina when he set off to fire a bullet through Walker's window on April 10, 1963..
I left you as much money as I could. $60 on the second of the month, and you and Junie can live for two months on $10 a week. If I am alive and taken prisoner, the city jail is at the end of the bridge we always used to cross when we went to town. In participating in the Walker hoax, Lee recognized that he was participating in a very dangerous game ( one in which he could be killed)
Lee also recognized that this mission ( a staged attempt to shoot JFK was extremely dangerous) and he might get killed ...