It sounds like you handled the situation well. I've been in a similar situation, I did handle it differently, but the scenario was different. I was on tour, and the crew was local and didn't know the show at all. I got a call from backstage that one of my actors was having problems, and the symptoms that were listed sounded like a stroke. It was near the end of the show, so I took a chance. I asked the hand with me in the booth if he could follow a prompt script, knowing that my sound tech knew the show well enough to run his own cues and that there were only a few light cues left in the show. I left my script with the hand and went backstage to deal with the situation myself, since I was SM & CM, as well as first aid certified. Backstage, I was able to organize the actors to get someone else onstage playing his part and then get him to where we could wait for an ambulance. The local hand backstage, while handling the situation fine in regards to contacting me etc. had never seen the show before and the other actors didn't know what to do, so me showing up with directions for everyone was the best thing to do.
Its also why I always cleaned up my prompt script at the beginning of every tour.
-Centaura