If he is indeed sick it is possible they are sick as well. Just keep an eye on them.
Look for:
*clicking/ popping noises
* excessive saliva (it will be bubbly and sticky)
*open mouth breathing and wheezing
*rubbing their faces on the cage and leaving saliva smears on it
*drooling
*anything that is really wrong/out of the ordinary
I'd recommend practicing tight quarantine procedures with the male in question. As in deal with him last, and don't mess with anyone else in the day afterwards. Wash up well before and after handling each snake. Etc.
From personal exp. :They won't catch an RI just being 3 ft from him. It takes direct contact with contaminated objects (cage, bedding, your hands, etc.) or sick snakes. Although for safety's sake, I recommend putting him as far from the others as possible, such as in a seperate room.
Keep in mind none of us are vets. Just try to take a deep breath and relax.