One of life's lessons from childhood also holds true in investigations. If I ask you a question today and contact you again later with the same question, will I get the same truth? As I was taught as a young lad, "If you tell the truth the first time, then you never have to remember what you told."
In other words, don't get tripped up by a falsehood you forgot to cover. If you get nailed for lying on an official investigation, this will be the end of a career. If you know or feel that a complaint is coming from a call or contact, prepare now. If you wrote an accurate report with all of the facts, you should be solid. Have on hand all of the names, numbers, and other contact information for all possible witnesses, which includes officers.
Give your supervisor a head's up that something may be coming over the horizon. This prevents surprises and may give your supervisor an opportunity to do some damage control as well. Now, do not be a chicken little and scream "The sky is falling!" with every field contact. As you become seasoned you will get a feel for when and when not to be worried.
If you do have a good reason to expect a complaint over an incident, sit down and recall the entire event; then document all you observed, said, or did. It is not what you do that can get you into trouble, but whether you document why you did what you did.
There are two caveats to this statement. One is that if what you said was composed with improper or unprofessional language, there may be no excuse; accept what you get, for you said it. Remember, if you have the urge to tell someone off because it will make you feel good, then don't say it! Secondly, if you have acted in a professional manner and within all guidelines, any citizen abuse cannot be tolerated.