@SharonNeedles encouraged me with her posts to look at this case differently rather than on the path of typical.
JMO I think PF and KB worked out a schedule where he was the M-F child caregiver, and she was the weekend parent. She is gone 12 hours every work day. He is a pillar at his ranch, and she is a pillar at her job, and the relationship may have worn out but still be friendly.
What if PF did pick up the baby 11/22 and that's the last he saw of her other than the 11/25 text? What if she told him while she loves her baby, she's just tired and wanted the 4-day holiday for a Me Time break? She could have willingly left to go anywhere with anyone, and I don't believe she tells her family everything. CB calls on 12/2 and PF isn't concerned because they aren't really together any more and he has the baby. If they aren't really together any more, he may not know where she would go either, not his problem and KB may have been not sharing personal info with him any more. In this scenario, PF has new problems, too, because the other parent is missing - so he is now the 24/7 parent with no backup. Also, PF is not related to KB, so it makes more sense that CB files the missing person report.
I'm just trying to see the situation from an innocent PF point of view, try it out. I couldn't care less about any ex of mine, what they do, where they go.