It kind of depends what you mean. A lot of us always said that the most important thing was that any day we went to work, we lived to go home. But, this does not mean that we would not have sacrificed our lives for that of a five year old child in a heartbeat. It was really more about using proper tactics instead of thinking we were super-heroes.
I also personally lived by a rule to never ever do anything that would cause me to not be able to look myself in the eye in the mirror. This is integrity. There are lots of opportunities to go astray, from something as "minor" as someone handing you a $20 bill folded discreetly beneath their driver's license when you pull them over on a traffic stop. It's your choice.