The CIA apparently launched MK Ultra because they were concerned that the Soviet Union had developed a powerful mind control drug. They had to keep up so they launched their own program to do research on mind control drugs.
If that's true and this was a weapon's program instead of some people with security clearances saying "Let's party dudes", wouldn't they have actually tried to control people's minds?
In this case, you've got a US Marshall who went from a Christmas Party to a robbery over the course of a bad trip. If you wanted a proof of concept that you could make a well connected Soviet official do something, how much better of a poc can you come up with?
I know this sounds conspiratorial and it is, but the CIA giving people LSD without their knowledge is a true conspiracy theory. I'm having a lot of trouble believing they'd just get people high, let them wander San Francisco and see what happens.