Remove Culpability
When I left my last net, that I built from the ground up, I was disgruntled as hell. So, I insisted the owners join me in the "closet" and I instructed them on how to change all admin account passwords in the AD... following secure criterion I drilled into them from Day 1. I made it very clear that I didn't want to know the new p/w's and I stood away where I couldn't see the screen nor keyboard.
Sure I could crack it, but then who would hire me to build/admin another net? Plus, if I need them for a reference, I know I can still list them.