Stryke, good questions and good answers by bill.
Giving the particulars of what you may have done in self defense to responding police officers may well be used against you, so, as you say, you have admitted to something that next you must defend in a court of law.
This may happen when you say something under the emotional turmoil following your survival situations while still in the grip of adrenaline that will cause, as Mas Ayoob terms:diarhhea of the mouth, totally disconnected from the brain.
This is a serious problem because any type of Combat is a ''traumatic psychic "shift." where even trained people can have difficulty applying physical and emotional 'training'…
Yet there has to be an affirmation of 'justification' for what the police will observe at the scene of your 'survival' i.e., self defense.
1. Legally as an affirmative defense, self defense must be pled in a timely fashion lest it be waived, according to what we read.
In an affirmative defense, the defendant affirms that the condition is occurring or has occurred but offers a defense that bars, or prevents, the plaintiff's claim. An affirmative defense is known, alternatively, as a justification, or an excuse, defense.
 Consequently, affirmative defenses limit or excuse a defendant's criminal culpability or civil liability.
A clear illustration of an affirmative defense is self defense.
 In its simplest form, a criminal defendant may be exonerated if he can demonstrate that he had an honest and reasonable belief that another's use of force was unlawful and that the defendant's conduct was necessary to protect himself.
 Most affirmative defenses must be pled in a timely manner by a defendant in order for the court to consider them, or else they are considered waived by the defendant's failure to assert them.
This is good reading:http://www.armedcitizensnetwork.org/you ... ain-silent
Attorney Andrew Branca writes
the difference between the burden of production–which the defendant DOES bear for purposes of self-defense, but which is merely a minimal showing of evidence to allow the issue to be heard by the jury–and the burden of persuasion–which is born by the state to DISPROVE self-defense beyond a reasonable doubt.
What is recommended, as Bill points out, is to master the mantra that you were in fear of your life or grievous bodily harm, to relate the simple why of it, point out to any weapons or disparity of size and force, any witnesses…but when it comes to your having to provide details of what you did, you should only say that you protected yourself from being killed or seriously hurt…that now you wish to remain silent…but will extend full cooperation after speaking to an attorney that you now wish to see immediately.
The caveat here is that we may not be able to follow these rules under the turmoil we'll find ourselves in and will fall prey to the natural instinct to tell all 'celebrating' our survival.
It also helps not to blow our own horn on these pages, trying to suggest how tough we are, how much training we have had, what we could do, what we may have done in the past and how 'lethal' we should be seen by the readers because of who and what we are. This is the best way to play into a prosecutor's hands.
I have seen this on these pages by a number of people now and then and I simply shake my head.
Why not tell the police what happened? You will do that, in due time. But realize that in times of great stress things get distorted as your mind focuses on the threat. That knife might appear much larger than it actually was. If you mention a huge knife to the cops, and it turns out that it was a penknife with a 1.5-inch blade, it will make you look bad. Likewise if the "crowd of robbers" turns out to be just two people swarming you. The 1.5-inch blade was still a deadly threat, and you have as much right to defend yourself against two knife-wielding thugs as against 20, but mistakes such as this will impugn your testimony in everything. Don't let it happen. Ask for a lawyer, shut up, and after talking calmly with an advocate, make a full statement.
As Bill says all this should be a part of your on the floor training…you repeat these things to yourself and or discuss them often with your students as you workout so that they deeply ingrain.