There are halachos about what, how and when to disclose sensitive shidduchim information. Also, savvy people don’t only call people listed on the resume.
Regarding publicizing bad contractors, or other business related things; there are likewise many details that go into such a shailoh. Is the guy ripping off people entirely? Is he just not the best? Did he make one or two isolated mistakes? And even then, you have to abide by all of the conditions laid out in the chofetz chaim, including approaching him first, going to his rov, verifying all information first hand and not going by other people’s reports, not using unnecessarily harsh language or exaggerating. Then there are times that you can only tell people who are going to use him, but not smear him all over social media – that can impact not just him, but his family too.