I learned to check tool offsets the hard way

Last week, I was running aluminum on our mill. I grabbed a program I used a while back and did not look at the tool numbers. The first piece came out okay, but then the cutter plunged way too deep and snapped. It turned out someone adjusted the tool height after fixing the machine, and I missed it. Now I have a busted cutter and a bunch of waste metal. I always run a quick test cut now before the full job. How do you all prevent stuff like this at your work?