If the firm is auditing the financials, presumably the tax returns should be clean and materially accurate. Where is the "bs return" coming from?
Couldn't the partner just have processed for paper filing and sent to the client via courier with filing instructions if the client refused to e-sign the efile authorizations?
That seems like it would mitigate risk exposure for both the firm and the partner if the client was being uncooperative (at least as far as tax services are concerned).
I think however, it's more complicated than that based on the article. It sounds like informational returns were not filed for some or all of the foreign subs, and some or all of the foreign sub income wasn't picked up when it should have been. Perhaps the partner or the firm was out of their depth, who knows.