Anyone else get burned by bad measurements before a big project?

Just wrapped up a commercial fit-out that almost went off the rails before it even started. The initial measurements we got from our contractor's guy were way off, and we discovered it way too late. A friend recommended I get a proper site survey done, and it literally saved the project from a massive (and expensive) delay.

I used the team at RPM Response and the difference was night and day. They brought in 3D laser scanners and provided a crazy detailed report with everything we needed.

Has anyone else had a similar close call? For those in construction or project management, when do you decide a dedicated site survey is a non-negotiable?