Not sure if you are saying that there was no verification whatsoever for the responses, or whether the attorney signed the verification form for the client.
An attorney is supposed to sign the responses especially if there are objections. Such is mandated under Code of Civil Procedure section 2031.250(c) and 2033.240(c).
The client is suppose to sign the responses under oath (also known as a verification) pursuant to Code of Civil Procedure section 2031.250(a) and 2033.240(a).
If your question relates to the attorney signing the verification, then the answer is provided under under Code of Civil Procedure section 2031.250(b) and 2033.240(b). Code of Civil Procedure section 2031.250 (b) provides: "If that party is a public or private corporation or a partnership or association or governmental agency, one of its officers or agents shall sign the response under oath on behalf of that party. If the officer or agent signing the response on behalf of that party is an attorney acting in that capacity for a party, that party waives any lawyer-client privilege and any protection for work product under Chapter 4 (commencing with Section 2018.010) during any subsequent discovery from that attorney concerning the identity of the sources of the information contained in the response."
Code of Civil Procedure section 2033.240 (b) is similar, with respect Request for Admissions.
Lawyers sometimes sign the proofs of service on discovery responses, which doesn't matter, but if a lawyer verifies the responses themselves, they will have waived attorney-client privilege. If there's no verification, then that's like getting no response at all.
If you're going to do your own liigation and not hire a lawyer, at least buy a good guide on civil procedure, like the 3 volume Rutter Guide.
Disclaimer: Please note that this answer does not constitute legal advice, and should not be relied on, since each state has different laws, each situation is fact specific, and it is impossible to evaluate a legal problem without a comprehensive consultation and review of all the facts and documents at issue. This answer does not create an attorney-client relationship.