I wouldn't say it's a glaring error. It's a stylistic choice, though I will agree that most style guides' guidance (yeah, I chose awkward wording because emphasis) is that you should use the 's after the word if it's singular and doesn't otherwise sound awkward with the extra syllable. Achilles' tendon, for example, would sound awkward if written as Achilles's tendon.

I think the argument could be made that business' sounds better, since business's could easily be confused with the plural form, and three consecutive S letterforms looks awkward. In fact, now that I think about it, I would've written it the same way.