This is not the job of an accounting firm. So no hey likely won't verify it, because again that is not their job or what they do.
Are you implying that an outside accounting firm doesn't perform routine audits of this company's financial statements, which would typically include the validity of charitable contributions?
Umm, yes I am. An accounting firms job in an audit is to verify there are no material misstatements and GAAP has been applied correctly.
In other words the auditing of financial statements is simply to make sure the companies accountants did their job correctly and there are no material mistatements.
They are not looking for fraud and if a company wanted to lie about a charitable contribution it would be effortless for them to get it past the auditors.