I just thought of a scenario that might convince me!
I’m chased into my house by strange creatures that exited a “space craft” and I shoot one in self-defense and the blood is color or consistency of Cheez-Whiz or a kale smoothie. But most likely I will still wonder what the CIA jabbed me with.
But what if it turns you shot a CIA agent during your hallucination?
Besides, if space aliens could travel 1000 light years across the galaxy, they probably would have a very good bullet-proof force-field.