I successfully changed the subject, for a few minutes. Then Ella piped up with 'But mama, look at his face -- he IS crabby.'
At this point I was trying really hard not to laugh, her comments were so innocent and were actually true -- this guy did have a grumpy look on his face. As I was trying to figure out what to say next (while trying not to make eye contact with anyone else in the waiting area, especially Mr. Crabby Face Man), Zoe piped up with 'Ella, he is concentrating, he is not dead'.
At that point I was hoping he was deaf, or at least didn't hear very well. Like Tom said later, if he wasn't crabby before he probably was if he heard our little conversation.
We did have a good talk on the way home -- but I'm sure this is just the beginning.
It's still making me chuckle though.