One of my buddies who is really into UFOs thinks he was abducted last night

One of my friends who I always talk to about UFOs is totally convinced he was abducted last night. He said he was in his bed and then he just remembers flashes of what happened after that, but he said he saw the outside of the craft they took him to and that it had symbols that looked like they were forged into the body of it.

He said they looked like stereotypical greys who had jumpsuits that looked like they were made of tin foil or something and that they communicated with him telepathically, but not with words. It was more of a feeling.

Anyways, I told him it’s pretty much guaranteed to be sleep paralysis and a dream, but he’s totally convinced and he drew these symbols he said he saw on the craft.

Any ideas?