Well, as I've said repeatedly on this thread, they should remember who the criminal is and who the victim is and act accordingly. Prosecute based upon intent, not based upon the caliber used.
I agree that they should prosecute based on intent. Here's an example on how caliber may be used to demonstrate intent. Suppose you have an average citizen who has a modest firearms collection, has several revolvers that he uses for "home protection". We'll call this citizen "Joe". Joe has his primary personal protection revolver that's a .357 magnum S&W 686, and his other home defense revolvers are .38 special made by various manufacturers. One day Joe hears someone fumbling around down stairs around 3am. He picks up his flashlight and his S&W 686 to see what's going on. He sees the shadows of what appears to be either very small men or 12 to 13 year old youths. At this point, he figures that they're unarmed, so he goes into his gun safe and retrieves his Sig Sauer Mosquito. He figures that he could use the .22 cal Mosquito to defend himself if necessary, but not necessarily kill the youths because they're young and have a long life ahead of them. He gets down stairs and the youths rush him. Feeling threatened, he unloads the 15 round magazine into the three youths. One youth bleeds out and dies while waiting for an ambulance, a second youth is critically injured due to a bullet to the head. The third youth manages to escape and check himself into a local hospital with a couple of bullets in his backside. Police arrive and question Joe, who states to the police that he would like to cooperate, but would like his attorney present before answering any questions.
Few hours later, attorney arrives at the police station and the police question Joe. He answers questions that his attorney advises him to, and cooperates to the best of his ability with the police. He's released pending further investigation. The police take his Sig Mosquito into evidence.
During the police investigation they discover that Joe has many firearms registered. The detectives wonder why he would use a .22 rather than his primary defensive firearm. Keep in mind that he never states anything to the police about wanting the youths to live a long life, or anything that would incriminate him. So far all he's stated was that he saw multiple BG in the house, retrieved his firearm, then was rushed by the youths while he attempted to get to the phone to call 911 (cell phones don't work where he lives, his only phone is in the kitchen).
Based on the fact that Joe had access to firearms that would have been able to stop the threat of three BG with knives rushing him, and the fact that he grabbed his .22 when he would have normally used a .357 mag or .38 spc, the police determine that the shooting wasn't justified and turn the case over to the prosecutor's office for review. Prosecutors determine that the guy had used a caliber that was inadequate for self defense due to the other options that Joe had. They charge him with negligent homicide (for the guy who bled out while waiting for an ambulance), and first degree assult with a deadly weapon (for the two youths that didn't die, but got shot), and reckless endangerment (for discharging a firearm in a residental neighborhood).
This case would have been a lot different if the guy didn't decide to in essence try to "scare" the youths. He should have used the adequate force necessary to stop the threat. In this case the police and prosecutors can argue that a .22 is not adequate to stop a threat. If Joe owned only a .22 caliber pistol, he could argue that this was his best (and only) option with regard to use of firearms. However, since he had other pistols that would have been adequate, the prosecutors can use that fact against him and argue that he did intend to "scare" the youths, but was overpowered by them while they tried to get away.
I'm not trying to start an argument or debate here, simply trying to show that there are times when police and prosecutors will come up with all kinds of theories that could put your average gun owner in jail. We as firearms owners need to be aware of the serious consequences of our actions. This is why I strongly recommend to all of my students that they should pick an appropriate caliber for their home defense pistol. There are some states that don't allow certain calibers to be carried for defensive purposes. I'm sure that we could find many cases that have gone to court if we looked hard enough.
Bottom line is that we should all be pro active in chosing what we carry. Consult competent legal counsel and familiarize yourself with the laws of your state and the states where you'll be traveling.
gf