“I know it was my friend’s spirit by what was said and how the medium described him.”
Having read extensively about how Houdini traveled the world exposing mediums as FAKE, revealing their tricks, showing how they deceive, etc., I doubt it was him - regardless of how it felt or looked.
Evil spirits are dodgy. They don’t WANT materialistic skeptics to budge from their materialism, because a viewpoint that denies the existence of spirit gives evil spirits a lot of room to do psychic mischief without anyone caring about the source of the problem. Anyhow, evil spirits won’t go out of their way to do their paranormal stuff for materialists, in most cases.