There’s no way you could use a law firm to violate U.S. election laws.
Unless you’re the Clintons, of course.
The law firm is certainly culpable and part of a criminal conspiracy if they knowingly violate federal law.
That seems to be what happened here.
Sorry but you are wrong on this, because the law firm is not the entity that must report to the FEC. The law firm simply claims they didn’t know what they were reporting to the FEC and the FEC would not have a leg to stand on. Thus they are not even going to include them. Were they culpable in reality, of course, but not that put them in any legal jeopardy. The filing is against the Clinton Campaign & DNC only, and never mentions the law firm in its complaint of campaign expenditure reporting violations.