Even if NASA and ESAB had a "miscommunication" (I suspect an unresolved contract issue, which both sides thought the other has accepted responsibility for owning the floor contracting), what should have happened is that the ESAB equipment people, before starting work on the installation should have inspected the floor work they mandated to make sure it was done correctly. If this happened at all, you'd assume someone who notice that the floor has not been recently rebuilt AT ALL and would stop work until that got done. If you say your equipment needs some part of the environment to be a certain way before you can install, presumably you don't do it until it meets spec. So, no matter who else is to blame, ESAB is negligent in proceeding with work if the floor had not been brought in line with requirements.
An alternate, plausible chain of events is that NASA originally, disagreed with ESAB and felt the floor fix was unnecessary in the first place and told them if they wanted to do it, NASA was not going to pay for that. ESAB does a risk assessment, decides there's a danger but it likely will work and goes ahead. Install fails and during resolution, NASA makes under-the-table concessions to make ESAB whole financially if they admit it's their screw-up. This perfectly reflects the difference between govt and corporate fears. NASA fears looking stupid and is probably willing to pay money to avoid that. ESAB is more worried about losing money and can always subtly imply privately to other future customers that it was NASA that screwed up.