WR, Be very careful and stay alert. Your h may not realize that you already know about his latest complaints that he fed his lawyer. Generally when they are nice and polite, they are up to something. I've seen this time and again and it's the dance. Next time, he'll be slamming you for something. It's the good cop/bad cop routine that they love to us on us. Please don't be lulled into a sense of security because he's not done yet.
BTW, if he's called your S14 a number of times, then he should wait for him to return the call or not. He should realize that if his son hasn't called him, maybe your son doesn't want to speak w/him. You need to get yourself out of the middle of this phone tag business and let the two of them deal w/it. I know you really want them to have a relationship...but your son is old enough to determine whether he wants to deal w/his father or not.
I do hope that you and your sons are doing well in spite of his latest antics.
Sit quietly, the answers will reveal themselves when you least expect them to. The past is gone, the present is a gift and you need to focus on today, allow the future to reveal itself when it is ready.