We tend to overestimate the healing power of an apology.
Research regarding this subject, done in 2012, got a new boost. David de Cremer, together with Marius van Dijke and others, conducted several studies on the subject and explain more in this article.
The article is also published here:
www.cambridgenetwork.co.uk/news/the-art-of-apologising/
www.iedp.com/Blog/The_Art_of_Apologising