It's not perjury unless it's willful. I have no doubt that some of these inconsistencies (most?) are deliberate, but human memory is often pretty terrible. Good luck proving that the officer was deliberately not telling the truth.
Well, usually this comes from written statements right after the event right? It's not like there's a several week gap between the event and the report.... right?
How about making it a crime to misremember? Sure would make you think twice before you testified something as fact. Human memory is _very_ fallible. Time we started treating it that way.