Usually people remember sharp details and forget those that were not so vivid. What people notice and remember depends on their own interests and experiences. Frequently people see what they expect to see, whether it was really there or not. People fill in gaps to make a story more believable. People build up a story in retelling it.
People often shorten a story in retelling it.
With regard to rumors, the bottom line is that, before acting, make certain you have all the facts.