What especially bothers me about this is that there was no accident report filled out and you were not called. I've worked with children for many years and ours rules have always been that parents are called for any injury on the head/face (if nothing else but to let them know it happened and is being monitored) and an accident report is always filed (parents are always aware of this). I know he didn't tell the teachers, and childcare workers don't have enough sets of eyes to go around so things are sometimes missed, but it should have been easy to notice since it was swollen and he was crying.
I definitely wouldn't cc the other parents, it's good you decided not to, but I would be having a meeting with the teachers to talk about what went on, and definitely about the texting. That is not okay.