It’s always no good idea to thank someone without the exact knowledge about the real work he or she had done and the exact period he or she were on duty. Such a commendation – especially in a published report or in a public speech looks to the one who get it the opposite, because it reflects that it is not worth the time to collect and check the correct data.
I read such commendation about my work on the LibreOffice extensions and templates website in the annual report of The Document Foundation today. I invested a lot of my spare time to work as a pure volunteer for the foundation and on the website for about eight years (I worked for about sixteen years inside the community of the free office software project).