Ran a 4 flute in 6061 at 8000 and you lasted 40 seconds? That is wild. The math on that is about 1000 surface feet per minute, which is flat out flying for a 4 flute in aluminum. Your chip load had to be near zero, so the tool was basically rubbing itself to death instead of cutting. I run around 3000 to 4000 RPM with a .003 to .005 chip load per tooth and my end mills last for weeks. The chart on the wall is there for a reason, and bay 4 just taught you that lesson the hard way.

Read a DAN article a while back about this exact thing, they said logging depth plus conditions helps you spot risk patterns you'd never remember on your own. I started adding a simple danger flag next to any entry where something felt off, whether it was current, viz, or just a gut thing. Three seasons in, two spots near a wreck I dive keep showing up over and over in those flags, and the funny part is I used to swear those dives were all fine.