They did have a good arrangement, as they lived close enough that each of them could watch the baby, potentially each on the same day.
Kelsey worked, so she had built in childcare. He might have had the same, if his mother watched the baby while both of them were working.
If custody was the motive, it’s likely because something changed, or was about to change.
But there really isn’t evidence of that right now, atleast as far as we have seen.
It’s still my primary motive, but there could also be others that we don’t know about.
Like a financial one.