He did what he could at the time. When he goes and gets her, document with police report. Then on Monday, call dr and get records, see if you can talk to dr too and see how bad she was. Email mom, and ask when make up time can be for missed visit, even if it is a dinner visit. Take what you can get. If you have other denials file for contempt of court (while there, add sentence that unless there is a dr note stating child can not come, the child will go with father, if child is sick with note, the father will get make up time the following weekend, same times.)
It is very emotional when you go and can not take your child. Your dh has to control himself and not ring his ex's neck. She has control of his kids right now and he can not do anything about it. It is very frustrating to watch but your dh is also dealing with a lot too and trying to make you happy.