The hardware store clerk who told me to ignore the manual
I was rebuilding a lawn mower engine about 10 years ago and a kid at Ace Hardware told me to skip the torque specs and just tighten by feel. Said he'd been doing it for years that way. I listened to him, got it all back together, and the head gasket blew after three starts. Cost me another 40 bucks and a whole Saturday to redo it. That clerk wasn't even working there a month later. Has anyone else gotten bad advice from someone who seemed confident but was just wrong?