First of all, only a few percent of people will deliver exactly on the due date. You may deliver at 38 weeks. After 37-38 weeks, anytime is possible. It is way too risky to stay in China until just a few days before the due date.Almost crazy to me.
Second of all, he should know that a father should be present when his wife delivers and when his child is born to the new world. It means a lot to both the wife and the child. When baby grows up what will he tell his child about the child's most important moment of life? Say "Sorry child, I missed your birth because I chose to stay in China at that time"?
One sentence, 不可思议。