Root canal or extraction?

I have several root canals and crowns. They are great. That said, I had one tooth that the dentist swore was fine, and I kept having pain every time I put pressure on it. I finally asked to have it pulled. The specialist that pulled it said it was cracked right down the middle. It was a huge relief.
that is what I am concerned about; is a crack he may not be seeing. that and the tooth moves around a bit.