I can not answer that one conclusively. I'm a dispatcher, not a psychologist or psychiatrist. My best recommendation is acknowledge you are having an acute stress reaction, get through the stressor as best you can and then deal with the aftermath as soon as possible. Just acknowledging you are having a bit of trouble should bring relief on it's own. A delayed stress reaction can be more confusing.
Some people have no reaction to a highly stressful event.
Either they don't have the time and luxury or it is their nature to automatically lock down emotionally. So, when odd things begin effecting their lives the connection to the stressor may not be immediately obvious. The scene may crop up without your willing it over and over and over again, interfering with your ability to focus, concentrate and function efficiently. These images may creep into your dreams as well. Flashbacks such as these can be prompted by external stimuli such as sight, sound, smell or touch.