Here is how he returned the favor on Facebook:
It is disqualifying for a modern-day presidential nominee to refuse to release tax returns to the voters, especially one who has not been subject to public scrutiny in either military or public service. Tax returns provide the public with its sole confirmation of the veracity of a candidate's representations regarding charities, priorities, wealth, tax conformance, and conflicts of interest. Further, while not a likely circumstance, the potential for hidden inappropriate associations with foreign entities, criminal organizations, or other unsavory groups is simply too great a risk to ignore for someone who is seeking to become commander-in-chief.
Mr. Trump says he is being audited. So? There is nothing that prevents releasing tax returns that are being audited. Further, he could release returns for the years immediately prior to the years under audit. There is only one logical explanation for Mr. Trump's refusal to release his returns: there is a bombshell in them. Given Mr. Trump's equanimity with other flaws in his history, we can only assume it's a bombshell of unusual size.
(Anticipating inquiries regarding my own tax release history, I released my 2010 tax returns in January of 2012 and I released my 2011 tax returns as soon as they were completed, in September of 2012.)
Romney did not defend himself.
@MittRomney it's no wonder every1 hates you— Women 4 Trump (@Women4Trump) May 11, 2016
Flashback 2012: Trump Defended Romney When Reid Attacked on Taxes - https://t.co/77c6qFBPQH