Until they have resolved their issues, they will bounce back and forth. If he was in withdrawal, then he was not trying to reconnect. They will reconnect the exact opposite of how they disconnected from people, pets, etc. You should be the last one he attempts to reconnect with.
Continue to be yourself, be the lighthouse in the storm. If he contacts you, take some time in responding and when you do, be friendly and just listen. Be a friend. He may very well try to reconnect when his issues are resolved.
