I'm sorry, but you have a terrible conception of Justice.
We should never think that prison "should" be the solution for anything. That's the reason there is 4.5 times more persons in prison per capita in US than in NZ [1].
In continental Europe we tend to consider that prison is there as a punishment for really severe things (killings, sexual abuse, severe drug trafficking etc.) OR a way to avoid reiteration. If there is no risk of reiteration and the damage was light, then fines and other non-socially disruptive punishments are better suited.
And your conception that : private citizens always end up in prison so should government representatives, is wrong. If private citizens always end up in prison, then that's a problem that should be solved... not ampliated by putting more people behind the bars. Your vision almost sounds to me like a bitter revenge : "Hiii, we pooooor citizens always go to jail, they should taste their own medicine". No, the least prison, the better.
The best example of this is your terrible transformation of an important Judicial principle. You wrote : « Better a few government employees behind bars "unfairly" than more than a few citizens behind bars "unfairly". »
Dude. Read yourself. There is no way, people behind the bars unfairly is better than anything. It's the wrost thing. Remember the Blackstone Principle : "better that ten guilty persons escape than that one innocent suffer".
And finally, do not forget that police is by essence making mistakes, it's impossible not to do, because they do something called investigation. If they were only to act in full certainty, then they would almost never act. They gather data and facts about a possible crime, and they have to use force to do that, and then they send all of this to a judge who will decide if there is enough to effectively find someone guilty or not. What you are asking for, is that police only act when they're so certain of the guilt that there is almost no need anymore for a trial. The judicial system cannot work like that. You must allow police force to make mistakes... or we're going to end up with police acting like Judge Dredd.
Which by the way does not mean there is not going to be any punishment, and if they do some really grave trespassing, then they might even end up in prison. It's a question of scale.
[1] http://www.nationmaster.com/graph/cri_pri_per_cap-crime-pris...