Someone threaten to put me in the sandbox should i alert Google? Or Adsense

[etui342]

I paid someone to make manual links and he send me the wrong excel and they did not link as they should. I told him that and he got pissed and wanted money anway. I said i want the right excel and i pay you.

He got even more pissed and say he use xrumer (no he tells me he use a software nice lie) to basically sandbox my Adsense sites.
1. Can he do that?
2. Is there anything i can do to stop it?

[talks44]

He can't do it, you just need to relax in your case.

[C.Rebecca]

You can deny him the backend access or terminate your services with this individual.
XRumer is a link blasting software that can get your site heavily penalized by Google, or worse.
Matt Cutts said in one of his videos that if your competitor is trying to insert crappy links on your site, Google will identify it and will not penalize your site.

To be on the safer side, make sure you keep doing SEO and making quality backlinks.