First, a review of the “Apology”:

It goes much deeper than just “donations to the Clinton Foundation”.  Clinton Cash author Peter Schweizer writes in a USA Today Op-Ed:

[…]  I agreed to be interviewed, expecting a robust examination of my new book, Clinton Cash, and my reporting on the Clintons’ accumulation of massive personal wealth, cronyism and the lack of transparency surrounding the Clintons’ foundation.
I expected probing questions, similar to the ones I’ve received from Andrea Mitchell on MSNBC, Chris Wallace on Fox News and Frank Sesno on CNN.
What I did not expect — what no one expected — was the sort of “hidden hand journalism” that has contributed to America’s news media’s crisis of credibility in particular, and Americans’ distrust of the news media more broadly.
If Stephanopoulos had disclosed his donations to the very foundation I was there to talk about, perhaps it would have put the aggressive posture of his interview with me in context.
But he didn’t.
And even though he has apologized to his viewers for keeping this information from both his audience and his bosses, there is much that Stephanopoulos has yet to disclose to his viewers. Indeed, far from being a passive donor who strokes Clinton Foundation checks from afar, a closer look reveals that Stephanopoulos is an ardent and engaged Clinton Foundation advocate.
For example, in his on air apology for this ethical mess, Stephanopoulos did not disclose that in 2006 he was a featured attendee and panel moderator at the annual meeting of the Clinton Global Initiative (CGI).
He did not disclose that in 2007, he was a featured attendee at the CGI annual meeting, a gathering also attended by several individuals I report on in Clinton Cash, including mega Clinton Foundation donors Lucas Lundin, Frank Giustra, Frank Holmes, and Carlos Slim — individuals whose involvement with the Clintons I assumed he had invited me on his program to discuss.
Stephanopoulos did not disclose that he was a 2008 panelist at the CGI annual meeting which, once again, featured individuals I report on in the book, such as billionaire Clinton Foundation foreign donor Denis O’Brien.
ABC’s most visible news employee did not disclose that in 2009, he served as a panel moderator at CGI’s annual meeting, nor did he disclose that in 2010 and 2011, he was an official CGI member.
Stephanopoulos did not disclose that in 2013 and 2014, he and Chelsea Clinton served as CGI contest judges for awards, in part, underwritten by Laureate International Universities — a for-profit education company I report on in the book. Bill Clinton was on its payroll until his recent resignation.  (read more)