Woot! I fixed a policy limitation at work by simply refusing to apply the policy as written and standing my ground. "Family" for purposes of sick/bereavement/etc. leave now includes anyone with which the employee has a "family-like relationship", not just "blood and law relatives"
I got into a little trouble by signing off on family leave for an employee whose dear friend ("she's like a sister to me") needed some medical support, but I stood my ground on the basis that we shouldn't be defining family in a way that excludes people our employees consider family. And I signed it off twice more.
HR threatened to fire me over it, but a whole bunch of my peers and a good chunk of my team basically went together to HR and my VP and said "he goes over this, we quit". Solidarity works!