Concerns About Implant Bone Grafting and Sinus Augmentation Surgery

My parent recently underwent an implant procedure after consulting with a dentist. The plan was to have two upper molars done, but one of them required bone grafting. However, during the bone grafting process, my parent experienced unexpected complications.

After anesthesia, my parent complained of loose front teeth and persistent pain. Upon further examination, the dentist discovered that the front teeth were cracked and required treatment. This has led to ongoing pain and frustration for my parent, who is now considering taking legal action against the dentist.

I have several concerns and questions about this situation:

1. Is it possible for front teeth to crack or become loose during implant bone grafting?
2. When we initially signed the contract, I was under the impression that only bone grafting would be performed. However, I later discovered that maxillary sinus augmentation surgery was also done. Was this procedure part of the original agreement?
3. My parent is also experiencing bone recession, which is causing further anger and frustration. Is it true that bone recession is a desirable outcome in this situation?

I am not familiar with dentistry and would appreciate any insight into these concerns.