No, it's a perfect example of the exact opposite.
Despite the fact that Vergo was covered in Haki, Law's fruit power cut right through him(and it was his fruit power, not his Haki, because otherwise Vergo would be dead). Because Haki doesn't nullify fruit powers. If it did, Law wouldn't have been able to use his on Vergo while he had his Haki up.
I'm not even sure why this is a debate. Robin has straight up said Haki doesn't negate a fruit user's powers.