Here's my 2 cents on the matter.
Let's assume your guess about your co-worker having Tourette's Syndrome is correct. I myself have tics, which are very common for people born with certain neurological and/or developmental disabilities, one of which I myself was born with. And because of this I've noticed other people, aka "normie folk" as I call them, interpret me as being unusual, "off", and weird. This could be the only reason why your co-worker acted the way he did.
You seem very confident that he saw your Spirit Friends, and are concerned that your co-worker might come after you, or are just concerned about Their safety, if I've read your post correctly.
In my opinion, I wouldn't be concerned. Other than anything related to magick, he can't do anything. If you're very uncomfortable about this, Creepy Hollows does offer a "cloaking" service that prevents other people from seeing and hearing your Spookies. You could try this:
https://shop.creepyhollows.com/binding- ... aking.html
or
https://shop.creepyhollows.com/portable ... tones.html
Remember, you are the leader in your Spirit Family, and what you say goes. If you don't want your Spirits to communicate with him, then you let Them know.