I don't think calling is going to do any good. He'll have gotten the message. Are any In-laws involved at all? Grandparents may want to know that their grandson is in the hospital, and they can apply some outside pressure.
I will say, her message was a tad passive aggressive. I know she's scared and hurting. I would just caution her in the future to just keep things less heated (I just wanted to let you know that S was in an accidnet yesterday and is in the hospital. He would like to see you (if that's true). He's at such and such hospital. the number is such and such)
M:26 H:32 T:8yrs ILYBNILWY/ "I'm not happy": 2/6/16 D-Day-discovered PA/EA: 2/10/16 Separated: 2/14/16 He's living with OW I moved to different state: 06/16 Currently: Trying to move forward