During my 24 years on the job there were quite a few occasions when I had to make decisions and take action in seconds, followed by lawyers debating my decisions and actions for years afterward.

If the courts determine that an illegal search was conducted the results of that search are not admissible in evidence. If it can be proven that the officer knowingly, willfully, or negligently violated a person's Constitutional rights then there may be penalties imposed on the officer(s) and their employers.

There are also some mistakes made in a good faith.

None of these matters are decided quickly or easily. But the cops still have to go out and try to do the job as best they can, knowing that there will always be criticism no matter what they do.

By the way, if this was a perfect world there would be no need for cops, or lawyers, or judges.