I was lining up a header pipe section at the plant outside Gary and trusted the old dial gauge showing zero, but the fit was off by nearly half an inch once we started pulling bolts. Turned out the gauge stem was bent from being thrown in the tool box, so I switched to a straight edge and a tape for the final lineup, which saved a rework call. Any of you guys run into a measuring tool that just decided to lie mid-job, and what do you check first when things won't line up?
Learned that lesson the hard way too, except mine was a level that had been dropped so many times it would tell you the leaning tower of Pisa was plumb lol. Now I check the tool against a known straight edge before I trust it on anything. Bent stems and sticky needles sneak up on you.