The laws regarding this are very different in different states/countries and if you are concerned you really need to ask a lawyer but...
You don't need a model release to sell a photo - do you think newspapers have model releases for all the photo they print? (especially the paparazzi ones).
Using a picture in ads of material connected to a company requires a model release because you are implying the model supports your company - and you don't want the model to decide he/she does not like your company and sue you.
It's perfectly legal (in most of the world) to publish someone's picture without permission as long as there's nothing offensive, you are not harming that person and you are not misrepresenting the person or his/her opinions (details vary by location).
Of course someone can always sue you anyway.
By the way, unless the photographer explicitly transferred the copyright then the pictures are still copyrighted by him (but, based on the story he is extremely unlikely to get upset when the pictures are published so everything will probably be ok)